Kudzu (Pueraria montana var. lobata) – Historical Profile

Written by: Brandon Holden, Alison Kilpatrick, Jonathan Sukhra, Lily Vuong

Canadian Kudzu population along the shores of Lake Erie
Canadian Kudzu population along the shores of Lake Erie near Leamington, Ontairo. Photo courtesy of Mike Cowbrough (Cowbrough, 2016).

HISTORICAL PROFILE

 The history of Kudzu, Pueraria montana var. lobata, started off in eastern Asia in primarily subtropical and temperate regions. The kudzu plant was introduced to the United States from Japan in 1876 at the Centennial Exposition in Philadelphia. The vine was widely marketed in the Southeast as an ornamental plant to be used to shade porches and later promoted as a forage crop (McGroarty, 2010). Concerns revolving around soil erosion through the 1930s and 1940s led the United States Department of Agriculture (USDA) to recommend the planting of Kudzu as a preventative measure along steep slopes throughout the south (Forseth & Innis, 2004). The Soil Erosion Service, a subsection of the USDA went on to provide approximately 85 million Kudzu seedlings to southern farmers, and paid them to plant the seedlings as a means to further prevent soil erosion throughout the Southern United States (Forseth & Innis, 2004; Grebner, Ezell, Prevost, & Gaddis, 2011). These activities were supplemented through a civilian corps movement that encouraged the planting of the vine in public lands and parks (Forseth & Innis, 2004). Due to governmental promotion, Kudzu had a solid hold throughout the Southeastern United States by the early 1950’s (Grebner et al., 2011). Even though Kudzu was removed from the list of permissible cover plants by 1953 (Grebner et al., 2011), declared a weed by 1970 (Hinman, 2011) and finally added to the noxious weeds list by 1997  (Grebner et al., 2011), the plant was able to spread throughout America and has made its way across the border into Canada. Kudzu is currently found on every continent with the exception of Antarctica (Gigon, Pron, & Buholzer, 2014 ).

In Canada, kudzu was discovered near Leamington, Ontario in 2009 and the population was estimated to be at least 8 years old at the time (Lindgren et al., 2013). It is not currently regulated as a pest under any legislation in Canada (Lindgren et al., 2013), nor does it have an official status as a noxious weed under the Weed Control Act (Waldron, 2012).

In  the United States, kudzu has been able to quickly grow over and shade other vegetation, causing damage to crops, orchards, and forest plantations. The greatest monetary impact of kudzu growth has been felt by the forestry industry where the productivity losses of entire young forest plantations have been estimated between $100 million and $500 million per year (Lindgren et al., 2013). There is also concern that kudzu can host soybean rust (Phakopsora pachyrhizi), and crop damage and yield losses have been a problem for farmers (Lindgren et al., 2013). In the United States, kudzu has damaged power lines which costs power companies an estimated $1.5 million per year (Lindgren et al., 2013). Kudzu has also reportedly grown over rail lines and caused derailments, costing railroad companies a significant amount in control costs (Lindgren et al., 2013). Costs of control in national and state parks are also reported to be considerable (Lindgren et al., 2013).

Using climate suitability models of current and future climate conditions, it has been predicted that changes in the global climate will allow for kudzu to spread northward (Lindgren et al., 2013). Waldron (2012) believes that it is likely that the kudzu population near Leamington, Ontario will spread further into southern Ontario unless measures are taken to control it.

ECOLOGICAL CONNECTIONS

 Kudzu is a specialized plant that will grow in certain conditions, thriving to r-strat_animal_yellowunmanageable states if presented ideal conditions, and if found in locations where survivorship is low, could take years for seeds to germinate (Lindgren, C. J. et al). Kudzu’s ability to rapidly grow and take over a deciduous forest canopy stand can surpass any healthy forest ecosystem’s tree growth. It is possible for the vine to have multiple canopy layers that can total the entire biomass of a deciduous forest canopy (Forseth & Innis, 2004).  Kudzu’s resilience to methods of eradication is strongly based on its large roots which store large amounts of starch, nitrogen, and water. The roots proficiency to grow into the substrate at 0.03 metres in depth a day, weighing over 180 kg and extending as deep as 3 metres is only one of many factors associated with the persistence of this plant (Forseth & Innis, 2004). This vine also has the ability to maneuver and redirect its leaf angles in relation to the direction of the sun; this is called paraheliotropism (Forseth & Innis, 2004). The leaves can be in positions to receive full sun, parallel to the sunrays to lower temperatures, and steep angles to prevent wilting (Lindgren et al., 2013). Kudzu’s adaptive qualities threaten local biodiversity through high competition for expanding room and below ground for roots. Studies have suggested that some of the common methods for controlling invasive vines, such as mowing, may be inadvertently causing the plants to grow back even more aggressively, which is something to consider when exploring management options (Kartzinel, Hamrick, Wang, Bowsher, Quigley, 2015). Kudzu is also a ‘structural parasite,’ meaning that, rather than supporting itself, it grows on top of other plants and buildings to reach light. Its ability to reproduce and spread quickly allows it to quickly cover shrubs, trees, and forests, where it blocks the sun’s rays from the plants below it, decreasing or eliminating their photosynthetic productivity (Miller & True, 1986).

CRITICAL ASSESSMENT OF MANAGEMENT OPTIONS

 The invasion of kudzu has proven to be costly to many industries in North America. With Kudzu being relatively new to Canada, and currently limited to a single outbreak, there is still a high probability that an effective management strategy can be implemented to control and eventually eradicate the vine from Canadian Shores. Some of the management options include doing nothing, grazing, chemical control, biological control, prescribed burning, and mechanical removal. These options are considered and assessed based on costs, benefits, and additional factors. Each option is explored in the following paragraphs and compared in Table 1.

There is the option to do nothing, however, seeing as kudzu is predicted to expand its range, this is not recommended. Kudzu will continue to be a burden on many industries if management of the species is not addressed. It may, however, be viable to focus efforts in controlling kudzu by utilizing it rather than removing it. One of these control measures is grazing by livestock. If heavily grazed on for 3-4 growing seasons, the root systems starve and this may effectively eliminate a kudzu population (Starr et al. 1999). However, vines can grow over fences and up trees, rendering them inaccessible to livestock (Lindgren et al., 2013).

A method used to manage kudzu populations is an herbicide called Glyphosate. In Mississippi, Glyphosate was used to tame kudzu and was successful in controlling 60-85% of the vine after 4 years (Lindgren et al., 2013). In some other states, regular use of Glyphosate with a backpack sprayer saw results of 80-100% success in just one season of use. Although herbicides have been effective against kudzu, it requires multiple and frequent applications (Minogue, Enloe, Osiecka, Lauer, 2011). Studies have shown that kudzu that has been controlled with herbicides, and shows no signs of growth, can emerge from its roots after a year, possibly more, of dormancy (Minogue et al., 2011). Some herbicide treatments have left the soil bare, making it difficult to reestablish native species, and does not halt the return of kudzu as it has no problem growing in disturbed areas (Minogue et al., 2011). In some cases, herbaceous species have been able to colonize areas where kudzu has been reduced chemically, however kudzu can return and overtop these species in a single growing season if the area is not closely monitored (Minogue et al., 2011).

Another form of control is prescribed burning. This process kills the foliage of the plant but also requires repeated applications to be effective (Starr, Martz, Loope, 1999).

There are several biological means that are already in place and more that may be implemented to control the growth of kudzu. Bacterial blights, insect herbivory, and insect seed predation occur in high levels in field populations of kudzu. Seed predation is quite prevalent, with up to 81% of seeds incurring damage in populations studied in North Carolina.  A study found two weevils that attacked the stems of kudzu and eight beetles that complete larval development in the kudzu roots. When evaluations of potential control agents are made, the range of the control agents must be considered. Efforts were made by the United States Forestry Service to find a biological control agent for kudzu. A “blackleg” fungus, a viral mosaic disease and a rust fungus have all been shown to cause mild injury to kudzu (Starr et al. 1999). Studies in China revealed that most of these biological control agents do not solely target kudzu, which is a risk to native species (Lindgren et al., 2013). More research needs to be done to determine the viability of biological control options.

Successful long term control of kudzu requires that the extensive root system be destroyed (Starr et al. 1999). As such, the mechanical removal of the entire root has proven to be effective in eradicating the species but is labour-intensive and time consuming (Starr et al. 1999). Another physical control method is close mowing but this requires frequent and repeated action (Starr et al. 1999). Close mowing has the same issues that grazing has as a control method because vines can grow up surfaces, which still requires alternative labour-intensive mechanical removal.

Table 1: Comparison of different potential management methods to deal with the invasive vine Kudzu. While time intensive, mechanical removal provides the greatest chance of success while reducing further negative impact on the environment.

Chart comparing the different Kudzu management method outlined above.

 

References

Cowbrough, Mike. (2016) Photo: Canadian Kudzu population, Lake Erie.

Forseth, I. N. Jr., & Innis, A. F. (2004). Kudzu (pueraria montana): History, physiology, and ecology combine to make a major ecosystem threat. Critical Reviews in Plant Sciences. 23(5):401-413

Gigon, A., Pron, S., & Buholzer, S. (2014). Ecology and distribution of the Southeast Asian

invasive liana Kudzu, Pueraria lobata (Fabaceae), in Southern Switzerland. EPPP Bulletin, 44(3), 490-501. Doi: 10.1111/epp.12171

Grebner, D. L., Ezell, A. W., Prevost, J. D., & Gaddis, D. A. (2011). Kudzu control and impact on monetary returns to non-industrial private forest landowners in Mississippi. Journal Of Sustainable Forestry, 30(3), 204-223. doi:10.1080/10549811.2011.530559

Hinman, K. (2011). Kudzu: how a wonder vine unveiled by Japan at the 1876 centennial began    eating America. American History, (2), 38.

Kartzinel, T. R., Hamrick, J. L., Chongyun, W., Bowsher, A. W., & Quigley, B. P. (2015).          Heterogeneity of clonal patterns among patches of kudzu, pueraria montana var. lobata, an invasive plant. Annals Of Botany, 116(5), 739-750. doi:10.1093/aob/mcv117

Lindgren, C. J., Castro, K.L., Coiner, H. A., Nurse, R. E., & Darbyshire, S. J. (2013). The biology of invasive alien plants in Canada (12): Pueraria montana var. lobata (Willd.) Sanjappa & Predeep. Canadian Journal of Plant Science. 93:71-95, doi:10.4141/cjps2012-128

McGroarty, M. J. (2010). How to control kudzu, the vine that ate the South. Kudzu’’ Retrieved from: http://www.freeplants.com/kudzu.html

Miller, J. H., & True, R. E. (1986). Herbicide tests for kudzu eradication. Georgia Forest Research Paper. Retrieved from https://www.srs.fs.usda.gov/pubs/misc/rp_gf065.pdf

Minogue, P. J., Enloe, S. F., Osiecka, A., & Lauer, D. K. (2011). Comparison of aminocyclopyrachlor to common herbicides for kudzu (pueraria montana) management. Invasive Plant Science and Management. 4:419-426

Starr, F., Martz, K., Loope, L. (1999). Kudzu (pueraria lobata): An alien plant report. United States Geological Survey Resources Division. Retrieved from http://www.hear.org/species/reports/puelob_fskm_awwa_report.pdf

Waldron, G. E., & Larson, B. M. H. (2012). Kudzu vine, pueraria montana, adventive in Southern Ontario. Canadian Field-Naturalist. 162(1):31-33

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Elk (Cervus canadensis) – Management Strategy

Written by: Justyna Van Poucke-Choquette, Christopher Reinhart, Ashley McNeill and Cassie Luff

r-strat_animal_outline

Management Plan: This plan provides details regarding the implementation and maintenance to managing Ontario’s Elk populations by using fencing as a method of keeping them out of pasture lands. With government agencies turning to non-lethal management method for protection of farmer’s crop and pasture lands, methods such as fencing will become increasingly important.  While there are multiple options for creating fences, the most effective option is a 3-D fence made of different heights and distances apart. (Johnson et. al., 2014). The fencing option is the most viable because it is a one time installment with slight maintenance of the fence afterwards. The cost of this type of fence is relatively minimal because all it requires is multiple, single wired fences spaced out. However, compared to the cost of not doing anything and letting the Elk continue on their feeding of pastures and stored crops would be exponentially higher and unfeasible for both the farmers and the government.  Another viable option for farms that currently have an existing fence could simply add more fences of different heights onto the original. Ideally a height of 6 to 8 feet will keep Elk out of the pastures, however by having multiple heights and distances it becomes harder for the Elk to jump over and navigate due to their poor depth perception. Farmers could even add an electrical component onto the 3-D fences to make them that much more effective. However, in Alberta, the success rate of the simple single wired multi fence method proved to have extremely high success at a rate of 75% effectiveness and therefore the addition of the electrical fence is unnecessary (Blair, 2016; Johnson and Burton, 2015). [JF3] , (Paige, 2015).  Once the Elk encounter this fence and try to get around it, they get stuck and tripped up in the fence, eventually getting frustrated and giving up (Knight, 2014; Blair, 2015). Through the introduction of this specifc fence type, optimal foraging will play a key role in persuading the Elk to not use their energy, in attempts to obtain a small quantity of food. By introducing a fence around pastures, it will eliminate Elk from being able to move into the pastures and consume the vegetation that is necessary for the survival of livestock. This is crucial because it is the simplest option for a problem that causes farmers massive losses in [JF4] pasture crops as well as stored crops. In a study done by the Peace River Forage Association of British Columbia, they calculated how much it would cost to create 3D fences for different areas including grain bag yard, hay stockyard, winter feeding and swath grazing. The winter feeding grounds and the swath grazing are the more relevant for this specific topic because the concern and problems are due to Elk entering the pasture area. The total construction costs of a 20 acre winter feeding area was $2140 and the total construction costs of a 160 acre swath grazing area was $5700 acres, which breaks down to $1140 per year. The same study also determined that the financial benefits of creating a 3D fence surrounding the swath grazing area would be $30,500 a year, $101 per cow. Comparing the savings, $30,500 to the costs of maintaining the fences each year of $1140, the benefits strongly outweigh the costs.  Information gathered from Ontario Ministry of Agriculture and Rural Affairs deemed that the Haliburton area has a total of 290 hectares of tame or seeded pastures and 1480 hectares for natural land used for pastures. This is a total of 1770 hectares for the Haliburton area, which also has the highest population of Elk in Ontario. This issue of crop destruction from Elk needs to be addressed, stored crops such as hay bales and silage bags, are not covered under the Ontario Crop Insurance Program and therefore cannot be covered by the government thus making the farmers pay for the losses out of their own pocket. Past historical management methods of Elk turned out to be devastating for the population. By the late 1800’s they were completely extirpated from Ontario (Hamr, et. al., 2016). Therefore we need to manage Elk that were recently introduced in a non-lethal way to ensure that this does not happen again.

Potential Challenges and Solutions: One concern with fencing large areas of land is reducing wildlife passage. If animals are not free to move through the property, for example in the case of a migration route, they are much more likely to attempt to breach the fence, and damage to the fence is the likely result. This can also result in the elk getting tangled in the fencing. For this reason, it is recommended that the fences are not built around any area larger than 640 acres (Knight, 2014). By limiting each side of the fence to one and a half kilometers or less, elk will be able to circumvent the fence without problem.  Another issue to be considered is that elk may be able to find weak spots in the fencing which can allow them to gain access to the pasture. To prevent this, simply maintaining the fencing will ensure that there are minimal weak spots.

Legal Factors: The use of fencing is a non-lethal management method, and therefore does not require any type of legal permits of any source. While farmers still need to apply for permits from the Fish and Wildlife Conservation Act to remove Elk by lethal means from their farms, they are not listed as any type of species at risk. The process of this application process can be long and challenging [JF8] [S9] and therefore the easiest methods would be to create a fence system that would eliminate the ability for Elk to enter into pastures. The only potential for this to require a type of permit is if the fence crosses a stream and somehow hinders the flow or has a post placed into the river itself. This could potentially require permits from the municipal level, and provincial level, as well as receiving permits [JF10] from the local Conservation Authority. The federal fisheries act is a long and powerful piece of legislation used to protect fish and fish habitats, and in the case of creating the fences this act will be taken into account. The provincial equivalent are the Fish Protection Act and the Riparian Areas Regulations. All of which provide protection for rivers and the riparian zones. These acts and regulations are often enforced by the county, township, etc.  This could entail inspection and studies to be done to determine if the creation of the fence would cause any significant harm to the river or riparian ecosystem. With all that said, it would be very easy to avoid placing any permanent structure into the river system by simple placing them on either bank and allowing the fence to stretch to either post.

 

Conclusion: The fence-extension is a viable option because it’s relatively low-cost to implement, depending on the circumstances. Since the Elk can jump 6-feet, they typically won’t do so just to get to an area to graze. The 3-D fencing is also a viable option, and can be very cost-effective. The options of installing a fence extension or a 3-D fence is humane and doesn’t require any Elk to get injured or killed for the benefit of humans. Because of this, there are no permits required to install these types of fences.

 

References

Knight, J. (2014, March). Modifying Fences to Protect High-Value Pastures from Deer and Elk. Retrieved from http://animalrange.montana.edu/: http://animalrange.montana.edu/documents/extension/modifiedfencesmg.pdf

 

Agency, P. C., & Canada, G. of. (2012, January 24). Parks Canada – elk island national park – background.   Retrieved January 27, 2017, from http://www.pc.gc.ca/eng/pn-     np/ab/elkisland/natcul/elkisland-we.aspx

Austin, D. D., P. J. Urness, and D. Duersch. 1998. Alfalfa hay crop loss due to mule deer depredation. Journal of Range Management 51:29–31

 

Blair, Jennifer. “Got Trouble With Wildlife On Your Pasture? Try 3D Fencing”. Alberta Farmer Express. June 16, 2015. Web. 17 Mar. 2017.

 

Hamr, J., Mallory, F. F., & Filion, I. (2016). The history of elk (Cervus canadensis) restoration in      Ontario. The Canadian Field-Naturalist, 130(2), 167. doi:10.22621/cfn.v130i2.1842

 

Haliburton County Community Food Assessment”. Agricultural Food Production and Consumption. N.p., 2017. Web. 31 Mar. 2017.

 

Innes, Robin J. 2011. Cervus elaphus. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory    (Producer). Available: http://www.fs.fed.us/database/feis/ [2017, February 11].

 

Johnson, Talon, and Burton, Sandra. 3D Fences Spread Across the Land. N.p., 2017. Web. 17 Mar. 2017.

 

Johnson, H. E., Hammond, M., Dorsey, P. D., Fischer, J. W., Walter, W. D., Anderson, C., & VERcauteren, K. C. (2014). Evaluation of techniques to reduce deer and Elk damage to agricultural   crops. Wildlife Society Bulletin, 38(2), 358-365. doi:10.1002/wsb.408

 

Knight, J. (2014, March). Modifying Fences to Protect High-Value Pastures from Deer and Elk. Retrieved January 27, 2017, from Montana State University,             http://animalrange.montana.edu/documents/extension/modifiedfencesmg.pdf

 

McCorquodale, S., P. Wik, and P. Fowler. 2011. Elk survival and mortality causes in the Blue Mountains    of Washington. Journal of Wildlife Management 75:897-904.

 

McIntosh, T.E., Rosatte, R.C., Hamr, J., & Murray, D.L. (2014). Patterns of Mortality and Factors    Influencing Survival of a Recently Restored Elk Population in Ontario, Canada. Restoration           Ecology, 22(6), 806-814. doi:101.111/rec 12145

 

Paige, J. (2015, November 2). Adding a third division to a wildlife barrier fence. Retrieved from Manitoba Cooperator: https://www.manitobacooperator.ca/livestock/adding-a-third-dimension-to-a-wildlife-barrier-fence/

Rosatte, R. (2014). 2014 Bancroft/North Hastings Elk Research and Monitoring Update. Ontario   Federation of Anglers and Hunters.

 

Ryckman, M. J., Rosatte, R.C., McIntosh, T., Hamr, J., & Jenkins, D. (2010) Postrelease Dispersal of Reintroduced Elk (Cervus elaphus) in Ontario, Canada. Restoration Ecology, 18(2), 173-180. DOI:10.1111/J. 1526-100X.2009.00523.X

 

Rhyan, J. C., Nol, P., Quance, C., Gertonson, A., Belfrage, J., Harris, L., & … Robbe-Austerman, S. (2013).   Transmission of Brucellosis from Elk to Cattle and Bison, Greater Yellowstone Area, USA, 2002-2012. Emerging Infectious Diseases, 19(12), 1992-1995. doi:10.3201/eid1912.130167

 

Wagner, K. K., R. H. Schmidt, and M. R. Conover. 1997. Compensation programs for wildlife damage in North America. Wildlife Society Bulletin 25:312–319.

Wildlife Population Management”. Tpwd.texas.gov. N.p., 2017. Web. 15 Mar. 2017.

 

Witmer, G. 1990. Reintroduction of elk in the United States. Journal of the Pennsylvania Academy of Science 64:131–135.

 

Yott, A., Rosatta, R., Schaefer J., Hamr, A., Fryxell, J. (2011) Movement and Spread of a Founding Population of Reintroduced Elk (Cervus elaphus) in Ontario, Canada. The Journal of the Society for Ecological Restoration International.

Wild Boar (Sus scrofa) – Management Strategy

By Reanna Moore, Kayla Berger, Ashtyn Dokuchie & Rhiannon Lace

Management Options

Over time, many management practices have taken place around the world, and few have had any lasting effect, especially when wild boar are not confined to islands. Among these options are:  shooting parties, culls and poisonings, government incentives, bounties, and using dogs (Oliver & Leus, 2008; Krull et al., 2016). While there have been marginal success stories with the extirpation of wild boar around the world, they have yet to occur in North America.

Killing wild boar (using whatever methods), has proven to be successful in removing the species only when they are completely eradicated; otherwise the species is able to bounce back, as history as demonstrated in Europe and Asia (Oliver & Leus, 2008). The total eradication of this species would be very difficult in North America, as they are incredibly adaptive and do not depend on a single food source or climate, and there is considerably more continuous land than in Europe. Furthermore, following the extirpation of the boar, there are consistent incidences of escape from farms, serving to potentially restore the population.

In several of the Southern United States, there is a bounty paid for killing wild boar, and they can also be found in restaurants as a main course. Despite years with these measures in place; the population persists. This fact would indicate that wild boar cannot be moderately controlled; if they are present at all in good conditions, then they will begin to thrive since they are ingenious at dispersing over large distances and repopulating.

The main reason to control wild boar is their tendency to destroy crops and to spread disease (as mentioned above). Since the environment (agricultural, rural) that promotes their survival cannot be controlled or kept from the wild boar, then it must be the other way around. Hence an important strategy for Ontario is to prevent wild boar from becoming an issue in the first place, and avoiding the heavy cost of destruction and difficulty of removing them entirely.

Management Matrix

           Considering that very few control strategies have found any degree of success alone, it seems that a combination of tactics would be most effective, some of which have been utilized, as well as some experimental and preventative measures to be explored as well.

Management Methods Cost Benefit Effectiveness
Shooting parties and poisonings – monetary

– time spent hunting for participants

– cost of poison

– personal danger involved

– killed boar can be used as food or sold

– less local destruction to agriculture

– although thousands of animals were eradicated this way, it had very little lasting effect
Bounties and use as food/trophies – monetary cost to government

– personal danger involved

– killed boar can be used as food or sold

– less local destruction to agriculture

– numbers were greatly reduced although not eradicated, likely due to the habitat restriction imposed by small islands
Eliminate the farming of wild boar, encourage hunting – monetary cost hiring researchers

– personal danger involved

– boar will be deterred from agricultural areas and pushed into the forest – numbers are reduced
This report will explore integrated monitoring and management techniques. – time and money for inventory

– cost to those profiting from game farms

– price of tagging

– boar will not become a problem

– avoids potentially millions of dollars of crop destruction

– if done well, there is a high likelihood for success

– program is adaptable based on conditions

– preventative rather than prescriptive

                          Historically, there have not been a wide variety of strategies employed to control wild boar populations, or adequate study to prove a significant level of effectiveness. As well, there are many seemingly contradictory situations in which boar are farmed (and escape), and hunters are encouraged to kill wild boar, while farmers continue to replace their stock, demonstrates a communicative disparity. Essentially, wild boar populations are maintained by human beings, and their desirability is dependent on their side of the fence.

           Management Plan

                      This plan provides details about managing wild boar populations under conditions specific to Ontario, and will discuss a combination of tactics and preventative measures to ensure that wild boars do not become a local issue. Damage to agriculture in the United States alone is estimated at 1.5 billion dollars annually, and this number is considered conservative, due to the difficulty of quantifying other negative impacts caused by wild boar, namely water contamination and interference with domestic pig populations (Tanger et al., 2015). In this case, preventative measures are much less expensive than a lack of action, which means allowing a local wild boar population to establish and dealing with the consequences.

                          In Ontario, there is no consistent population of wild boar, and historically sightings are only reported following incidences of escape from game farms, followed by several years without any record of wild boar. For this reason, measures will be outlined for preventing the initial establishment of a wild population, either from population immigration or game farm escapees, followed by methods to mitigate hypothetical growing populations under the failure of prevention.

                          The first method of control is to complete an inventory of Ontario’s game farms and boar populations. This could be instigated by a private organization or volunteers using an online database, to which the farmers have access. The inventory will include the number of boar, gender ratio, ages (mature versus juvenile) and location. As a further precaution, pigs could microchipped with a unique identification number. In case of an escape, the specific farm (with the distance from starting location) and the individual’s record could be recorded and taken into consideration for further decision making. It would be wise to collect data on farms outside of Ontario as well, in neighbouring states and provinces, since wild boar can disperse fairly quickly over large distances.

                          Due to recent data (shown below in Table 2.), as the number of farms using wild boar as alternative livestock has been declining in recent years, a cap on the number of farms may not be necessary, as long as there are regulations for containing, transporting and monitoring wild boar. The number of wild boar processed in registered meat plants (Table 3.) has remained consistent through the past five years, and as such the risk associated with wild boar escapes appears to remain constant, rather than growing.

Table 2. Census of Agriculture, selected livestock and poultry data, Canada and provinces, every 5 years (number) (Statistics Canada, 2012).
Ontario 2001 2006 2011
Wild boars Number of farms reporting 58 38 14
Number of animals 1,499 1,006 473
Average number of animals 26 26 34
Table 3. Number of Alternative Livestock and Gamebirds Processed for Meat in Ontario in Provincial and Federal Registered Plants Years: 2015 – 2011 (Tapscott, 2016).
2015 2014 2013 2012 2011
Wild Boar 487 536 561 392 396

           In continuation, it is advised to devise regulations applied to every farm containing wild boar in order to prevent escapes. There are currently no relevant regulations, as hunting wild boar on game farms (private hunting ground) does not require permits or game tags, and is neither covered by the Fish and Wildlife Conservation Act, nor the Game and Fish Act. The protocol could include acceptable types of fencing to be used on farms and limits on the number of male boar within a given population. A penalty system for incidences of wild boar escape could be put in place to provide additional motivation to properly contain the species, starting with fines escalating in price (based on severity), before the right to possess wild boar entirely is removed.

            On the occasion that a wild population does become established, it would become necessary to ban the import of the species and implement limits (or prohibition) on breeding captive populations. There is already an authorization in effect from the Ministry of Natural Resources and Forestry, which allows for the killing of feral pigs under the authority of a small-game license. Each region could employ local groups of hunters or animal control units, to be deployed in case of a wild boar escape. This would involve determining the source of the escaped animal (by contacting nearby farms), and tracking the wild boar until captured or killed. An animal that has escaped once is more likely to attempt further escapes, and it may be necessary to kill the animal rather than returning it to captivity.

Furthermore, the MNRF has already requested that any sightings be reported immediately, and this fact could be publicized throughout social media and news bulletins in affected areas. If wild boar become an issue in Ontario, game farms and the possession of captive boar will be increasing regulated and if necessary, eliminated completely.

Legal Considerations

                      Laws relevant to the control of wild boar fall, for the most part, under the Fish and Wildlife Conservation Act, 1997, S.O. 1997, although the act does not apply to farmed animals (Government of Ontario, 2017). The use of poison is prohibited under the FWCA, and keeping game wildlife requires a license under this act[JF16] . In acknowledgment of the negative potential of escaped wild boar, it would be advisable to offer a limited number of licenses to possess the animals within game farms in Ontario. The Trespass to Property Act is also important to consider if hunting or tracking of wild boar is to occur.

Wild boar sightings and killings must be must be reported to the Ministry of Natural Resources and Forestry (Legal Information, 2016). Wild boar are allowed to be hunted under the small games hunting act, this in under the fish and wildlife conservation act under section 54 (5). More information about sighting or reporting incidents can be reported to Mary Dillion, who is a management biologist with the MNRF.

 

           Potential Challenges and Solutions

                      The logistics of completing an inventory of game farms, and any other captive wild boar in Ontario and the surrounding area, may come to depend on the willingness of farmers and locals to participate. One source of motivation from their perspective, is that the prevention of wild boar escapees or an established wild population means that locals can keep their captive populations and businesses with less interference and regulation. Creating a centralized, online database would serve to make the inventory accessible and current, while ministry employees, volunteers or local animal control units could be employed to carry out the inventory, as well as randomized annual visits to ensure accuracy and compliance.

                          In the event of a wild population becoming established, a prominent idea to motivate hunters is to create a bounty for the killed animals. If this is done, it must be done with consideration that this may promote the breeding and subsequent release of animals, in order to attract the monetary incentive. A possible solution is that the bounty, in partnership with the tagging (with a unique identification number or barcode) of each animal, may serve to track the original location of the animal and its farm,  and as such, the farm’s right to possess the wild boar can be removed if there is a suspicious number of escapes. The idea of bounty becomes more realistic in tandem with the inventory described above, although it must be approached with caution nonetheless.

           Conclusion

                          In conclusion, while there are no significant populations of wild boar currently in Ontario, their presence in neighboring provinces and states, as well as their proficiency in colonizing new ecosystems and regions indicates that they are a realistic threat to Ontario’s crops, biodiversity and local captive pig populations (Pastick, 2014). With the cost of destruction to other regions in mind, preventative methods immediately present the most viable solution and prove to be much more practical and cost effective than allowing wild boar populations to establish. It is recommend that an inventory of game farms and other captive wild boar in and around Ontario be taken, while the import and transportation from outside sources be regulated and monitored. The farms possessing wild boar as game animals or alternative livestock will require a certain level of fencing and monitoring to take place. Each individual animal must be microchipped and any wild boar escapes recaptured immediately. This proactive approach will prevent Ontario from re-living much of the destruction that the rest of the world has suffered, and a rare opportunity to learn from other regions and countries, prior to making the same mistake.

Gray Wolf – Management Plan

Management Plan

This plan provides details about the implementation and maintenance of a strategy that will use livestock protecting dogs (LPDs) to mitigate the impact of wolf predation on cattle. Although LPDs have been used for over 2,000 years, there is much still to be learned about how to effectively implement their use in current livestock rearing operations (Gehring et al., 2010). As such, this management plan will rely heavily on monitoring the success of the solution and effective communication between the livestock owner, experienced LPD handlers, and the community of farmers already using LPDs (Gehring et al., 2010; VerCauteren et al., 2012). Consistent data collection will also contribute to expanding the knowledge of how effective LPD solutions are and how they may be improved. The following paragraphs will address the method of implementation including information about which breeds to use, when dogs will be introduced, how long it will take for the dog pack to establish and key responsibilities of ranchers who chose to implement this strategy. Clear expectations about the effectiveness of this management strategy will also be communicated for a variety of situations ranging from fenced in livestock to free range situations. Different breeds are available and care should be taken to select the appropriate breed or combination of breeds. Each breed of LPD has different traits that make them most suited to different situations. Table 3 below provides a summary of LPD breeds and their characteristics and recommended uses.

Table 3: Comparison of dog breeds and their characteristics. Mixed packs often form the best defense against multiple predators including Gray Wolves.

Breed Characteristics Strengths Issues
Great Pyrenese Large but less aggressive than other breeds, moderately long hair Placid and easy to manage relative to other breeds Generally not effective with large aggressive predators
Kangal Large and aggressive breed, heavy bodied with large head Very territorial and protective of livestock, Can be difficult to manage and may be an issue in areas where other dogs and people may intrude on pasture
Spanish Mastiff Large and alert breed, heavy bodied with large head Territorial and protective of livestock, not particularly active May not patrol as regularly as Kangal

Legal Factors

The use of LPDs eliminates the need for any additional legal permits as this is a non-lethal means of reducing predation by wolves. Any method that involves trapping, relocating or killing wolves requires permits as the wolf is an endangered species in the and permits under the Fish and Wildlife Conservation Act. Furthermore, legal implications exist at both the state and federal level in the form of the Endangered Species Act and Fish and Wildlife legislation. Although Federal legislation applies to all states the variation in state level legislation makes implementing solutions in multiple states an issue if permits or changes to legislation are required.

Establishing Livestock Protecting Dogs

Livestock protecting dogs and livestock take time to become acclimatized to each other. In most cases, acclimatization begins with effectively bonding the dogs with the herd. Minimal contact with humans is essential as the dogs should be focused on life with the herd and not seeking to be with humans (VerCauteren et al., 2012). Pups are most likely to bond effectively with livestock between the ages of 3-12 weeks; however, they should remain with their mother until the age of approximately 6 weeks which reduces this window of opportunity to the ages of 6-12 weeks. In some instances, bonding can occur up to 16 weeks of age. Ensuring that bonding occurs at the location where the dogs will be working is ideal. Care must be taken when bonding pups with cattle as cattle are much larger than sheep and goats presents a risk of injury to the pups. VerCauteren et al. (2012) recommend bonding pups with one or two 1 month old calves before exposing them to larger members of the herd. This provides a close bond with animals they will be protecting while protecting the dogs from injury by larger cattle. Even when bonding with calves, pups should be provided with a sturdy and safe refuge containing straw bedding that calves cannot access (VerCauteren et al., 2012).

Introduction to pastures should begin between the ages of 6-7 months. Handlers should introduce the dogs to the pasture with their bonded calves and ensure the dogs are walked around the perimeter of the pasture daily to help the dogs understand the boundary of the pasture and begin to establish their territory (VerCauteren et al., 2012). For most dogs, this routine will need to be carried out daily for one and a half to two weeks at which time the dogs can be left with the cattle unsupervised. After 7 months, the dogs and their bonded calves can be introduced to larger pastures with other cattle. Cattle that have been exposed to LPDs are treated very differently than cattle that have not been exposed to LPDs. Naïve cattle pose a serious risk to small puppies so great care must be taken to ensure the puppies are agile enough to evade any nervous cattle that perceive the puppies as a threat. Research indicates that dogs will approach LPD-naïve cattle differently than experienced cattle. Naïve cattle are approached in a more submissive manner by the dogs while experienced cattle are approached and greeted by the dogs without any signs of dominance or submission (VerCauteren et al., 2012). Watching for the development of these behavours and interactions will be critical in assessing how LPDs and cattle are acclimatizing to the situation.

Potential Challenges and Solutions

As with all solutions, there are unwanted challenges and consequences of implementation. For example, dogs may wander too far from the herd or they may not behave aggressively enough toward the target predator. Cases of dogs abandoning their herd and actually resorting to attacking livestock in adjacent areas are uncommon but documented (VerCauteren et al., 2012). If livestock are free ranging on public lands, as is the case in much of the U.S. northwest, hikers and their dogs may inadvertently come into contact with herds of cattle and the associated dog pack that is providing protection. In these circumstances, conflict between the LPDs, hikers, and pet dogs may be an issue. Education and effective communication are essential in these circumstances (VerCauteren et al., 2012). Finally, dogs are animals individual temperaments and behaviours regardless of their breed. Anyone employing this method of livestock protection must be willing to either commit to the time needed to train dogs or spend the money to hire dog handlers. Table 4 summarizes common problem behaviours and suggested methods for correction.

Table 4: Common issues encountered when working with livestock protecting dogs (LPDs). Note the causes and the methods that will help avoid the issue. In most cases, selecting the correct breed and sufficient effort during the training stages will resolve the issue (adapted from VerCauteren et. al., 2012)

Problem Behaviour Caused by Remedied by Avoided by
Roaming Too much human contact; female in heat; too much motivation to hunt wildlife; week bond with herd; companion dog moved Electric or invivislbe fencing; spay/neuter; shock collar; replace with herd-oriented breed/individual Provide only necessary attention; raise with effective LPD; spay/neuter; retain dog with the herd from the beginning
Aggression toward livestock Lack of early discipline; immaturity; play behaviour; adolescent phase of development Increase attention and reprimand; shock collar; replace with less aggressive breed or individual; remove from livestock and temporarily place in herd with more aggressive livestock; provide toys Consistent reprimand for chasing; rais with effective LPD; employ appropriate breed; minimize potential for boredom
Aggression toward humans Underlying breed characteristics or lack of socialization; territorial behaviour; protecting object, food or female; novel behaviour of humans toward LPDs; learned aggressive behaviour; pack behaviour; fearful temperament Replace with less aggressive dog or breed; increased attention and reprimand; shock collar; enrichment of environment occupied by puppy during socialization Employ appropriate breed; provide adequate levels of socialization with humans and environment
Lack of concern over offending species Lack of training or too much pressure by offending species; dog too young; weak temperament; female in heat; wounds Provide supplemental training with encouragement to address target species; place dog in a pack of experienced dogs or provide an experienced dog; ensure high quality food and health Provide early encouragement to exclude target species; employ appropriate breed; give appropriate food; regular health care
Insufficient protection against offending species Underlying breed characteristics; illness; female in heat; not enough dogs; environmental factors Replace dog or breed with a more aggressive breed; regular health care; incorporate alternative prevention tools such as electric fence and calving protection zones Employ appropriate breed; rear in area with offending species; monitor health; supply with alternative prevention tools; employ more dogs
Lack of obedience and ability to handle Insufficient training during the 7-12 month period; fearful temperament Increase frequency of training; maintain regular contacts until the dog is adult; avoid fearful pups Provide early and consistent training until adult and adequate level of socialization with handlers
Lack of attentiveness toward livestock Insufficient or bonding too late; illness; female in heat; old dogs Replace with effective dog; medical checkup Follow recommended bonding procedures; monitor health
Ineffective protection Insufficient bonding; illness; too large of an area; too much pressure Replace with effective dog; medical checkup; disperse resources: food, water, and shelter; employ additional dogs; employ other prevention tools Employ appropriate breed; raise in area with offending species; monitor health; be aware of limits of the dog
Insufficient patrolling of area Too large of area; lack of encouragement to establish territory Disperse resources: food, water, shelter; provide encouragement to explore territory; replace with more territorial breed Conduct routine walks with dog on lead within area to be protected

Additional methods of control may be needed including the installation of electric or invisible fencing fencing to keep the dogs in the pasture. In situations where the cattle are ranging over a large area or an area that is not fenced in, great care should be taken to monitor the herd and the dogs to ensure dogs remain with the herd. Multiple dogs may be needed for large areas and large herds. Finally, LPDs are a tool that will reduce but not completely eliminate all possibility of predation on livestock. Management of the heard and the dog pack are required to ensure success.

Conclusion

Livestock protecting dogs offer a non-lethal means of displacing wolves from areas where livestock are being raised. This method of management hinges on the nature of wolves and their ecological niche. The dog pack essentially occupies the territory effectively and provides a form of competitive exclusion that reduces wolf predation. No permits are required to implement this strategy and it satisfies the needs of livestock owners and environmentalists alike. Livestock protecting dogs are an ecologically sound solution to resolving conflict between humans and wildlife while satisfying the priorities of all stakeholders involved in this controversial issue.

Referneces:

Alcock, J. (1993). Animal Behaviour (5th ed). Sunderland: Sinauer Associates Inc.

Bergstrom, B. J., Vignieri, S., Sheffield, S. R., Sechrest, W., & al,  et. (2009). The Northern Rocky Mountain gray wolf is not yet recovered. BioScience, 59(11), 991–999. http://doi.org/10.1525/bio.2009.59.11.11

Blanco, J. C., & Cortés, Y. (2007). Dispersal patterns, social structure and mortality of wolves living in agricultural habitats in Spain. Journal of Zoology, 273(1), 114–124. http://doi.org/10.1111/j.1469-7998.2007.00305.x

Creel, S., & Rotella, J. J. (2010). Meta-analysis of relationships between human offtake, total mortality and population dynamics of gray wolves (Canis lupus). PLoS ONE, 5(9). http://doi.org/10.1371/journal.pone.0012918

Emerson, U. (2016a). EnviroNews | The Environmental News Specialists The Final Frontier of Investigative Reporting.

Emerson, U. (2016b). Federal Government Sued for Killing Wolves in Oregon. Retrieved February 4, 2016, from http://environews.tv/020416-wildlife-services-program-sued-for-killing-wolves-in-oregon/

Fritts, S. H., Bangs, E. E., Fontaine, J. a, Johnson, M. R., Phillips, M. K., Koch, E. D., & Gunson, J. R. (1997). Planning and Implementing a Reintroduction of Wolves to Yellowstone National Park and Central Idaho. Restoration Ecology, 5(1), 7–27. http://doi.org/10.1046/j.1526-100X.1997.09702.x

Gehring, T. M., VerCauteren, K. C., & Landry, J.-M. (2010). Livestock Protection Dogs in the 21st Century: Is an Ancient Tool Relevant to Modern Conservation Challenges? BioScience, 60(4), 299–308. http://doi.org/10.1525/bio.2010.60.4.8

Hansen, I., Staaland, T., & Ringsø, A. (2002). Patrolling with Livestock Guard Dogs: A Potential Method to Reduce Predation on Sheep. Acta Agriculturae Scandinavica, Section A – Animal Science, 52(1), 43–48. http://doi.org/10.1080/09064700252806416

Hawley, J. E., Gehring, T. M., Schultz, R. N., Rossler, S. T., & Wydeven, A. P. (2009). Assessment of shock collars as nonlethal management for wolves in Wisconsin. Journal of Wildlife Management, 73(4), 518–525. http://doi.org/10.2193/2007-066

Hawley, J. E., Rossler, S. T., Gehring, T. M., Schultz, R. N., Callahan, P. a., Clark, R., … Wydeven, A. P. (2013). Developing a new shock-collar design for safe and efficient use on wild wolves. Wildlife Society Bulletin, 37(2), 416–422. http://doi.org/10.1002/wsb.234

Mazur, K. E., & Asah, S. T. (2013). Clarifying standpoints in the gray wolf recovery conflict: Procuring management and policy forethought. Biological Conservation, 167(2013), 79–89. http://doi.org/10.1016/j.biocon.2013.07.017

Mech, L. D. (2014). The Challenge and Opportunity of Wolf Populations Recovering. Conservation Biology, 9(2), 270–278.

Mech, L. D., & Fieberg, J. (2015). Growth rates and variances of unexploited wolf populations in dynamic equilibria. Wildlife Society Bulletin, 39(1), n/a–n/a. http://doi.org/10.1002/wsb.511

Mladenoff, D. J., Haight, R. G., Sickley, T. A., & Wydeven, A. P. (1995). A regional landscape analysis and prediction of favorable gray wolf habitat in the northern Great Lakes region. Conservation Biology, 9(2), 279–294.

Otstavel, T., Vuori, K. A., Sims, D. E., Valros, A., Vainio, O., & Saloniemi, H. (2009). The first experience of livestock guarding dogs preventing large carnivore damages in Finland. Estonian Journal of Ecology, 58(3), 216–224. http://doi.org/10.3176/eco.2009.3.06

Perry, S. (2012). The gray wolf delisting rider and state management under the Endangered Species Act. Ecology Law Quarterly, 39(April 2011), 439–474. http://doi.org/10.15779/Z381V9K

Rich, L. N., Russell, R. E., Glenn, E. M., Mitchell, M. S., Gude, J. A., Podruzny, K. M., … Nichols, J. D. (2013). Estimating occupancy and predicting numbers of gray wolf packs in Montana using hunter surveys. The Journal of Wildlife Management, 77(6), 1280–1289. http://doi.org/10.1002/jwmg.562

Riley, S. J., Nesslage, G. M., & Maurer, B. A. (2004). Dynamics of early wolf and cougar eradication efforts in Montana: Implications for conservation. Biological Conservation, 119(4), 575–579. http://doi.org/10.1016/j.biocon.2004.01.019

Rossler, S. T., Gehring, T. M., Schultz, R. N., Rossler, M. T., Wydeven, A. P., & Hawley, J. E. (2012). Shock collars as a site‐aversive conditioning tool for wolves. Wildlife Society Bulletin, 36(1), 176–184. http://doi.org/10.1002/wsb.93

Rutledge, L. Y., Patterson, B. R., Mills, K. J., Loveless, K. M., Murray, D. L., & White, B. N. (2010). Protection from harvesting restores the natural social structure of eastern wolf packs. Biological Conservation, 143(2), 332–339. http://doi.org/10.1016/j.biocon.2009.10.017

Singh, M., & Kumara, H. N. (2006). Distribution, status and conservation of Indian gray wolf (Canis lupus pallipes) in Karnataka, India. Journal of Zoology, 270(1), 164–169. http://doi.org/10.1111/j.1469-7998.2006.00103.x

Smith, D. W., Bangs, E. E., Oakleaf, J. K., Mack, C., Fontaine, J., Boyd, D., … Murray, D. L. (2010). Survival of Colonizing Wolves in the Northern Rocky Mountains of the United States, 1982-2004. Journal Of Wildlife Management, 74(4), 620. http://doi.org/10.2193/2008-584

Smith, J. B., Nielsen, C. K., & Hellgren, E. C. (2014). Illinois resident attitudes toward recolonizing large carnivores. Journal of Wildlife Management, 78(5), 930–943. http://doi.org/10.1002/jwmg.718

Smith, M. E., Linnell, J. D. C., Odden, J., & Swenson, J. E. (2000). Review of Methods to Reduce Livestock Depradation: I. Guardian Animals. Acta Agriculturae Scandinavica, Section A – Animal Science, 50(4), 279–290. http://doi.org/10.1080/090647000750069476

Sommers, A. P., Price, C. C., Urbigkit, C. D., & Peterson, E. M. (2010). Quantifying Economic Impacts of Large-Carnivore Depredation on Bovine Calves. Journal of Wildlife Management, 74(7), 1425–1434. http://doi.org/10.2193/2009-070

Stohr, W. G. (2012). Trophic Cascades and Private Property: The Challenges of a Regulatory Balancing Act and Lessons the UK Can Learn from the Reintroduction of the American Gray Wolf. University of Baltimore Journal of Land and Development, 2, 15–52. http://doi.org/10.1017/CBO9781107415324.004

Van Bommel, L., & Johnson, C. N. (2014). Where do livestock protecting dogs go? Movement patterns of free-ranging Maremma sheepdogs. PLoS ONE, 9(10). http://doi.org/10.1371/journal.pone.0111444

VerCauteren, K. C., Lavelle, M. J., Gehring, T. M., & Landry, J. M. (2012). Cow dogs: Use of livestock protection dogs for reducing predation and transmission of pathogens from wildlife to cattle. Applied Animal Behaviour Science, 140(3-4), 128–136. http://doi.org/10.1016/j.applanim.2012.06.006

Way, J. G., & Bruskotter, J. T. (2012). Additional considerations for gray wolf management after their removal from Endangered Species Act protections. Journal of Wildlife Management, 76(3), 457–461. http://doi.org/10.1002/jwmg.262

Wielgus, R. B., & Peebles, K. A. (2014). Effects of wolf mortality on livestock depredations. PLoS ONE, 9(12), 1–17. http://doi.org/10.1371/journal.pone.0113505

Grey Wolf – Historical Profile

 Historical Profile

The history of the Gray Wolf, Canis lupus, in North America mirror’s it’s history in Europe. The European perspective of wolves arrived with settlers in the 1600’s and 1700’s and initial interactions were not confrontational because both wolves and humans were fearful of each other(Fritts et al., 1997; Stohr, 2012). As time progressed, settlers established larger farmsteads with more livestock resulting in the displacement of both wolves and their prey (Mazur & Asah, 2013; Stohr, 2012). The result was conflict between the remaining wolf packs that switched their food source to livestock. Pressure from landowners and ranchers resulted in a government sanctioned war on wolves with bounties paid for wolf hides in the late 19th century. More than 5,000 wolves were killed in the first year of this eradication effort (Emerson, 2016b). By the 1930’s wolves were almost extirpated from all western states with only a few animals remaining and very few viable breeding packs.

Image of old church ruins in Yellowstone National Park
The ruins of an old church in Yellowstone National Park illustrate the long history of humans on this landscape (Photo: Feltham, 2010).

Nothing changed in this regard for a long time. Wolves remained absent from the U.S. northwest without any viable populations in Yellowstone National Park. However, in 1995, 15 wolves were released in the park in an attempt to restore the population (Fritts et al., 1997). The effort was a success and wolves are now well established in the park with a population so large that it has become a source population for areas outside the park. Consequently, wolves and ranchers are again at odds because of wolf predation on livestock (Emerson, 2016a; Mazur & Asah, 2013; Stohr, 2012). The situation in areas around Yellowstone National Park has returned to conditions prior to the eradication of the gray wolf. Wolves are common and livestock losses are a regular occurrence. One element has changed. Wolves are a protected species now which prohibits ranchers from taking action and killing wolves that encroach on their land and kill livestock (Hawley et al., 2013; Hawley et al., 2009; Rossler et al., 2012).

Ecological Connections

r-strat_animal_outlineThe success of the eradication effort relates directly to the life history of wolves and their social nature. Wolves are k-strategists with slow population growth and populations that tend to stay stable at carrying capacity (Mech & Fieberg, 2015). Although wiping out the dominant male and female will result in subordinate females going into heat, the success of hunters and trappers generally resulted in the death of most of the pack leaving only a few animals dispersed over a wide landscape (Mech & Fieberg, 2015; Mech, 2014; D. W. Smith et al., 2010). Reproductive success was insufficient to counteract the mortality rate induced by human eradication efforts and population decline could not be reversed (Riley, Nesslage, & Maurer, 2004).

Vector_HumanIssues associated with reintroduction and a healthy wolf population are consistent with wolf ecology. Wolves are an apex predator that has adapted through social means to prey on large herbivores (Alcock, 1993; Vaughan, 1986). Humans have displaced native herbivores such as bison and elk in the areas surrounding Yellowstone National Park and replaced them with large domesticated herbivores such as cattle and sheep. For wolves, the landscape is essentially the same as it was without humans. Livestock and wild game are really no different from the ecological perspective of wolves. Therefore, losses in the ranching industry related to wolf predation are not unexpected.

Finally, reintroduction of species into a landscape where they have been absent for a long time frequently results in population growth that is so aggressive that the population overshoots the carrying capacity and then cycles above and below the carrying capacity before stabilizing. Wolf populations in the vicinity of Yellowstone can be expected to exhibit the same cycles resulting in some periods of larger than average wolf population. The abundant domesticated food supply reinforces this trend because larger, denser predator populations can be supported when there is abundant food (Rich et al., 2013).

Critical Assessment of Management Options

Wolves have been reintroduced successfully in a landscape where they were absent for more than half a century (Fritts et al., 1997). The success of this reintroduction has resulted in renewed conflict between wolves and ranchers. Four primary options are considered here and assessed based on costs, benefits, and additional factors. The options are; do nothing, eliminate wolves from the landscape, cull wolves, and livestock protecting dogs. Each option is addressed in the following paragraphs.

Doing nothing is always an option. In some situations, taking action may result in more harm than good or taking action will may not result in any real change resulting in wasted resources of time and money. Not taking action on this issue is not a viable option. First, the cost of monitoring losses and compensating ranchers for the predated livestock is too high (Sommers et al., 2010). With no revenue associated with this pay out, the cost is a drain on the U.S. economy. Secondly, the confidence of ranchers has already been eroded because the U.S. Fish and Wildlife Service, National Park Service, and multiple environmental groups have gone back on their word. The wolf population has grown to a size well beyond the size indicated in initial agreements to allow the reintroduction of wolves to the area (Mech, 2014). Yet, no action has been taken to mitigate the impact of these wolves on the ranching industry. Finally, decisions regarding the status of endangered species are being made by unqualified and misinformed politicians who are trying to please their constituents (Mazur & Asah, 2013). The result is a dangerous precedent for public pressure taking priority over sound science in environmental decision making (Way & Bruskotter, 2012). Taking no action will only serve to exacerbate the situation.

History_Newspaper
Wolves were successfully extirpated from most of the U.S. in the past and they could be again. However, the effort put into reintroduction and opposition from environmental groups prevent this option from being a viable solution now. (Photo: New York Times, 2015)

Extirpating wolves is an option. Wolves have been successfully eliminated as a threat to livestock in the past and they can be eliminated again (Riley et al., 2004). The result would be satisfactory to ranchers and it would eliminate much of the cost associated with the need to compensate ranchers for their losses. Eliminating wolves would potentially generate revenue in the form of permits to hunt wolves in the states where they are deemed to be a problem. Unfortunately, the pressure from environmental groups both inside and outside the U.S. has already resulted in the wolf populations growing beyond the initial agreed upon population size(Mazur & Asah, 2013; Perry, 2012; Smith et al., 2014) Environmental groups have lobbied successfully to keep the wolves on the endangered species list and they have even been responsible for law suits against the federal government over practices used to manage the current conflict (Emerson, 2016a).  The opposition to this method of resolving the conflict will be too strong.

History_Dead_Wolf
Culling wolves has also been used as a management strategy. However, recent research indicates that reducing the number of wolves may result in pack splintering and an increase in livestock predation. (Photo: New York Times, 2015)

Culling wolves is another option to be considered. Culling wolves in areas outside the park should effectively reduce populations and reduce predation on livestock. Both ranchers and moderate environmental groups could support this option. However, data suggests that this solution is unlikely to successfully reduce livestock predation (Wielgus & Peebles, 2014). If the alpha male and or female are eliminated from the pack and some pack members remain, the pack generally falls into a state of social chaos where the remaining pack members struggle to re-establish social order (Rutledge et al., 2010). Packs often splinter and become multiple smaller packs and some individuals end up on their own(Creel & Rotella, 2010; Rutledge et al., 2010). When this happens, multiple females may actually go into estrous (heat) resulting in an increase in the number of wolf cubs produced in the area. The splinter packs and lone wolves also continue to turn to livestock as a food source. Consequently, livestock predation may actually increase after a cull (Rutledge et al., 2010; Wielgus & Peebles, 2014). Therefore, consistent and ongoing culling of the wolf population will result in potential for more wolves and more livestock predation.

Dogs
Livestock guardian dogs may be a viable option in some circumstances. These dogs form a pack that occupies the pasture and excludes the wolves from the territory. Different breeds are used to form a pack of dogs that is loyal, protective, and formidable. (Conservation Media, 2013)

An ecological approach to resolving the conflict may be the most viable option. Livestock protecting dogs have been used for centuries to protect livestock from large predators ranging from wolves to big cats (Gehring et al., 2010; Hansen et al., 2002). The success of this strategy centres on the concept that the dogs occupy the ecological space/niche where the livestock are raised which excludes occupation by large, wild predators such as wolves. Livestock protecting dogs play the role of a wolf pack(Gehring et al., 2010; Van Bommel & Johnson, 2014). Some livestock losses will still be a reality but the frequency of predation will be dramatically reduced and dogs may even have a positive influence over the prevalence of pathogens spread by other wildlife species (VerCauteren, Lavelle, Gehring, & Landry, 2012). The economic cost of this option is greater than extirpating wolves. However, the cost is far less than the cost of doing nothing and more economically and ecologically sound than culling wolves (Gehring et al., 2010; Hansen et al., 2002; Otstavel et al., 2009; Smith et al., 2000; Van Bommel & Johnson, 2014; VerCauteren et al., 2012). Research tracking the success of this option in North America is lacking; therefore, implementation of this solution should be accompanied by research to fully understand the economic, social, and ecological implications of using livestock protecting dogs to protect livestock. Table 2 provides a visual summary of the options presented above.

Referneces:

Alcock, J. (1993). Animal Behaviour (5th ed). Sunderland: Sinauer Associates Inc.

Bergstrom, B. J., Vignieri, S., Sheffield, S. R., Sechrest, W., & al,  et. (2009). The Northern Rocky Mountain gray wolf is not yet recovered. BioScience, 59(11), 991–999. http://doi.org/10.1525/bio.2009.59.11.11

Blanco, J. C., & Cortés, Y. (2007). Dispersal patterns, social structure and mortality of wolves living in agricultural habitats in Spain. Journal of Zoology, 273(1), 114–124. http://doi.org/10.1111/j.1469-7998.2007.00305.x

Creel, S., & Rotella, J. J. (2010). Meta-analysis of relationships between human offtake, total mortality and population dynamics of gray wolves (Canis lupus). PLoS ONE, 5(9). http://doi.org/10.1371/journal.pone.0012918

Emerson, U. (2016a). EnviroNews | The Environmental News Specialists The Final Frontier of Investigative Reporting.

Emerson, U. (2016b). Federal Government Sued for Killing Wolves in Oregon. Retrieved February 4, 2016, from http://environews.tv/020416-wildlife-services-program-sued-for-killing-wolves-in-oregon/

Fritts, S. H., Bangs, E. E., Fontaine, J. a, Johnson, M. R., Phillips, M. K., Koch, E. D., & Gunson, J. R. (1997). Planning and Implementing a Reintroduction of Wolves to Yellowstone National Park and Central Idaho. Restoration Ecology, 5(1), 7–27. http://doi.org/10.1046/j.1526-100X.1997.09702.x

Gehring, T. M., VerCauteren, K. C., & Landry, J.-M. (2010). Livestock Protection Dogs in the 21st Century: Is an Ancient Tool Relevant to Modern Conservation Challenges? BioScience, 60(4), 299–308. http://doi.org/10.1525/bio.2010.60.4.8

Hansen, I., Staaland, T., & Ringsø, A. (2002). Patrolling with Livestock Guard Dogs: A Potential Method to Reduce Predation on Sheep. Acta Agriculturae Scandinavica, Section A – Animal Science, 52(1), 43–48. http://doi.org/10.1080/09064700252806416

Hawley, J. E., Gehring, T. M., Schultz, R. N., Rossler, S. T., & Wydeven, A. P. (2009). Assessment of shock collars as nonlethal management for wolves in Wisconsin. Journal of Wildlife Management, 73(4), 518–525. http://doi.org/10.2193/2007-066

Hawley, J. E., Rossler, S. T., Gehring, T. M., Schultz, R. N., Callahan, P. a., Clark, R., … Wydeven, A. P. (2013). Developing a new shock-collar design for safe and efficient use on wild wolves. Wildlife Society Bulletin, 37(2), 416–422. http://doi.org/10.1002/wsb.234

Mazur, K. E., & Asah, S. T. (2013). Clarifying standpoints in the gray wolf recovery conflict: Procuring management and policy forethought. Biological Conservation, 167(2013), 79–89. http://doi.org/10.1016/j.biocon.2013.07.017

Mech, L. D. (2014). The Challenge and Opportunity of Wolf Populations Recovering. Conservation Biology, 9(2), 270–278.

Mech, L. D., & Fieberg, J. (2015). Growth rates and variances of unexploited wolf populations in dynamic equilibria. Wildlife Society Bulletin, 39(1), n/a–n/a. http://doi.org/10.1002/wsb.511

Mladenoff, D. J., Haight, R. G., Sickley, T. A., & Wydeven, A. P. (1995). A regional landscape analysis and prediction of favorable gray wolf habitat in the northern Great Lakes region. Conservation Biology, 9(2), 279–294.

Otstavel, T., Vuori, K. A., Sims, D. E., Valros, A., Vainio, O., & Saloniemi, H. (2009). The first experience of livestock guarding dogs preventing large carnivore damages in Finland. Estonian Journal of Ecology, 58(3), 216–224. http://doi.org/10.3176/eco.2009.3.06

Perry, S. (2012). The gray wolf delisting rider and state management under the Endangered Species Act. Ecology Law Quarterly, 39(April 2011), 439–474. http://doi.org/10.15779/Z381V9K

Rich, L. N., Russell, R. E., Glenn, E. M., Mitchell, M. S., Gude, J. A., Podruzny, K. M., … Nichols, J. D. (2013). Estimating occupancy and predicting numbers of gray wolf packs in Montana using hunter surveys. The Journal of Wildlife Management, 77(6), 1280–1289. http://doi.org/10.1002/jwmg.562

Riley, S. J., Nesslage, G. M., & Maurer, B. A. (2004). Dynamics of early wolf and cougar eradication efforts in Montana: Implications for conservation. Biological Conservation, 119(4), 575–579. http://doi.org/10.1016/j.biocon.2004.01.019

Rossler, S. T., Gehring, T. M., Schultz, R. N., Rossler, M. T., Wydeven, A. P., & Hawley, J. E. (2012). Shock collars as a site‐aversive conditioning tool for wolves. Wildlife Society Bulletin, 36(1), 176–184. http://doi.org/10.1002/wsb.93

Rutledge, L. Y., Patterson, B. R., Mills, K. J., Loveless, K. M., Murray, D. L., & White, B. N. (2010). Protection from harvesting restores the natural social structure of eastern wolf packs. Biological Conservation, 143(2), 332–339. http://doi.org/10.1016/j.biocon.2009.10.017

Singh, M., & Kumara, H. N. (2006). Distribution, status and conservation of Indian gray wolf (Canis lupus pallipes) in Karnataka, India. Journal of Zoology, 270(1), 164–169. http://doi.org/10.1111/j.1469-7998.2006.00103.x

Smith, D. W., Bangs, E. E., Oakleaf, J. K., Mack, C., Fontaine, J., Boyd, D., … Murray, D. L. (2010). Survival of Colonizing Wolves in the Northern Rocky Mountains of the United States, 1982-2004. Journal Of Wildlife Management, 74(4), 620. http://doi.org/10.2193/2008-584

Smith, J. B., Nielsen, C. K., & Hellgren, E. C. (2014). Illinois resident attitudes toward recolonizing large carnivores. Journal of Wildlife Management, 78(5), 930–943. http://doi.org/10.1002/jwmg.718

Smith, M. E., Linnell, J. D. C., Odden, J., & Swenson, J. E. (2000). Review of Methods to Reduce Livestock Depradation: I. Guardian Animals. Acta Agriculturae Scandinavica, Section A – Animal Science, 50(4), 279–290. http://doi.org/10.1080/090647000750069476

Sommers, A. P., Price, C. C., Urbigkit, C. D., & Peterson, E. M. (2010). Quantifying Economic Impacts of Large-Carnivore Depredation on Bovine Calves. Journal of Wildlife Management, 74(7), 1425–1434. http://doi.org/10.2193/2009-070

Stohr, W. G. (2012). Trophic Cascades and Private Property: The Challenges of a Regulatory Balancing Act and Lessons the UK Can Learn from the Reintroduction of the American Gray Wolf. University of Baltimore Journal of Land and Development, 2, 15–52. http://doi.org/10.1017/CBO9781107415324.004

Van Bommel, L., & Johnson, C. N. (2014). Where do livestock protecting dogs go? Movement patterns of free-ranging Maremma sheepdogs. PLoS ONE, 9(10). http://doi.org/10.1371/journal.pone.0111444

VerCauteren, K. C., Lavelle, M. J., Gehring, T. M., & Landry, J. M. (2012). Cow dogs: Use of livestock protection dogs for reducing predation and transmission of pathogens from wildlife to cattle. Applied Animal Behaviour Science, 140(3-4), 128–136. http://doi.org/10.1016/j.applanim.2012.06.006

Way, J. G., & Bruskotter, J. T. (2012). Additional considerations for gray wolf management after their removal from Endangered Species Act protections. Journal of Wildlife Management, 76(3), 457–461. http://doi.org/10.1002/jwmg.262

Wielgus, R. B., & Peebles, K. A. (2014). Effects of wolf mortality on livestock depredations. PLoS ONE, 9(12), 1–17. http://doi.org/10.1371/journal.pone.0113505

WATER HYACINTH, (EICHHORNIA CRASSIPES) & WATER LETTUCE, (PISTIA STRATIOTES) HISTORICAL PROFILE

Written by: Reid Van Kuren, Andrew Base & Arden Ehrenberg

Historical Profile of Water Hyacinth, (Eichhornia crassipes) :

The origins and expansion of Water Hyacinth, (Eichhornia crassipes) are largely agreed upon by experts as having expanded from tropical South America (Kaufman, 2007). The evidence is not only fossil based or calculated by its preferred habitat, but was clearly recorded through trading documents and expedition journals from the late 1800’s  as natives from the amazon region began to explore and trade with their northern neighbours (Day, 2003). Water Hyacinth plants would be brought along on expeditions to be used for medical purposes. As settlers, explorers, and traders utilized and discarded these plants, the theory is that the plant waste would have been introduced to many aquatic and semi aquatic ecosystems across North America. (Castello, 2010). Some of these areas include the southern states of Texas, Louisiana, and Florida. Since Water Hyacinth’s ideal temperature range is 25-30 °C, these perfect climate conditions, combined with vast water bodies, likely allowed it to spread to water basins not directly visited by travellers. Water Hyacinth is considered extremely aesthetic and was often traded to settlements or offered as prizes (Day, 2003). These are the same criteria which allowed Water Hyacinth to expand to Africa, South Asia, and Australia in the 1880’s, and the Congo and river Nile in the 1950’s. Not only would these areas meet the Water Hyacinth species preferred growing conditions, but would have likely been used for the same purposes since it would have been impossible for Water Hyacinth to naturally disperse that far. (Castello, 2010).

Currently, Water Hyacinth is found around the entire world in both freshwater and salt water locations, often in slow or stagnant water basins. Since it can survive or thrive in the min/max range of 12-35°C, the only places Water Hyacinth is not found are polar and sub-polar regions. For example, Russia, Norway, and most of Canada are too cold for its growth and therefore do not need to worry about its invasive nature. Water Hyacinth has been found in Southern Ontario however, as it shares the same climates as Michigan or Maine.

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Ecological Connections

Water Hyacinth has earned the title as a nuisance species for the same reason as all other pest species – it’s negative and destructive effect on human inhabited areas. While the ideal temperature for Water Hyacinth is 25-30 °C, it can grow rapidly and withstand temperatures as low as 12°C and high as 35°C, meaning it has a broad temperature tolerance.  Water Hyacinth is known as an r-strategist species; it grows rapidly, and as a species it is tough to kill. While not all invasive species are considered nuisance species, Water Hyacinth shares many human-favoured habitats, such as saltwater shorelines, or freshwater rivers, streams, and lakes. The plant has caused problems for boaters, fishermen, and hydro generation as it outcompetes local organisms, gets caught in nets, lines, engines, and water passages (Oyani, 2011).

Water Hyacinth will grow in warm and stagnate or slow moving water, but it can also survive colder and faster moving waters. It may not grow in this situation, but it will survive and it will travel until more favourable conditions are found. Water Hyacinth reproduces using two methods. The first, is its typical r-strategy of reproduction, meaning each plant will send out hundreds of seeds to cultivate in the surrounding ecosystem. Many will die or fail to take root, but some will survive and cultivate, forming new plants along the shore, or in rich soils (Oyani, 2011). The other is its ability to reproduce vegetatively. Rather than rely on seeds, Water Hyacinth will sprout lateral shoots, which form stems, and fan out into new plants creating a mat (Castello, 2010). This process is repeated until all the surface water is covered, or the plant is damaged/destroyed enough to prevent it. If Water Hyacinth is not managed, or there is not a natural hindrance to its growth, the surface mat will eventually block out the sun, preventing underwater species from receiving energy. Once this occurs, photosynthesis decreases, oxygen levels decrease, and underwater organisms will die. Water Hyacinth is also known to choke out shoreline plants.

Assessment of Management Options

There are typically four primary management strategies used to combat Water Hyacinth around the world: Herbicides, machinery, manual removal, and competing species introduction. It is important to note that in nearly all situations and countries around the world, management strategies have failed. Despite research, monetary investment, and various tactics used by multiple governments and industry experts; existing methods have often been insufficient to contain the aggressive propagation of the weed and viability of its seeds.(Gichuki, 2010).

Even though Water Hyacinth can find preferred growth conditions across the equatorial zones, not all cultures have the same opinions or issues with Water Hyacinth. In Brazil for example, there is a local beetle called the N. buchi, which feeds on Water Hyacinth and is able to curtail the spread and reduce its abundance to less destructive levels (Richardson, 2003). By keeping shorelines clear, and allowing patches to form in the mats, aquatic ecosystems can still perform their functions unimpeded. In New Zealand and controlled parts of the U.S., Water Hyacinth is cultivated for medicinal purposes, similar to the pioneers of the late 1800’s, but on a much grander scale (Richardson, 2003).

For areas without a natural management option, the effects of Water Hyacinth can be much more severe. In Kenya, local fisherman and boaters require passage and the ability to fish for their livelihoods and survival. The government there has spent millions building and using machines to “chew up” the mats of Water Hyacinth, but these efforts have failed as the plants regrow and expand too quickly, and the costs of the operations become too much to be worthwhile (Oyani, 2011). There has not been a proven management strategy yet in Kenya.

Regarding herbicide, pesticide, and other chemical use; this method is considered cheaper, but also risks degrading soil and water quality through contamination, and risks bioaccumulation. Different chemicals such as Glyphosate and 4-D acid have been used in Ontario, but due to the volume and resilience of Water Hyacinth, the use of chemicals cannot keep up with the spread of this water weed (Gichuki, 2010). While the results are effective and immediate, the adverse effects on other organisms is often too great a risk.

Perhaps one of the biggest failures in management practices is the lack of cooperation and unification among communities. Despite being a banned aquatic species across the United States, Africa, and other countries – Water Hyacinth is still grown recreationally in private ponds, or sold in nurseries (CLOC, 2015). The combination of the above failures, mixed with the unwillingness from the community suggests another management option: do nothing. For the time being, Water Hyacinth may be a species that is best dealt with by accepting its resilience, and only taking action in the most required or extreme cases where the most harm is occurring.

Table 2. Management methods and evaluations for  Water Hyacinth

Management Method Direct Costs Benefits Drawbacks Efficacy
No Action N/A N/A Continued spread and nuisance.
Herbicides & Chemicals $ Targeted eradication. Contamination, and reduced water and soil quality. +
Manual Removal $ Safest route. Confirmed removal of species. Not effective. Species will regrow too quickly, or return. +
Machine Removal $$$ Quick and efficient. Environmental damage, costly, ineffective. +/-
Alternative Species $$ Natural and effective control of species. Unintended consequences, i.e. damage to other species or ecosystems. ++/–

Historical Profile of Water Lettuce, (Pistia stratiotes)

Historically, water lettuce has become widely distributed throughout the world due to its wide range of use as an ancient medicine, and as such, it is believed that it had been brought along with migrating human populations as they moved from one region of the world to another (Sculthorpe, 1971). Being a plant that reproduces vigorously in tropical and sub-tropical climates, it quickly spread and established large colonies once introduced to areas where it could easily sustain itself. Likely originating from Africa and South America, the water lettuce soon began to establish itself in Central Asia, South East Asia, most Oceanian Countries, southern Europe and finally in Central America along with parts of North America (Langeland, 1998) (EddMaps, 2017). This is largely due to the increase in commercial shipping, as it is hypothesised that cargo ships had the potential to carry water lettuce seeds in their ballasts (OFAH/OMNR, 2012), resulting in the wide dispersion of this aquatic plant species. Eventually, people began to use this plant decoratively in theirs garden gardens, aquariums and ponds, further exacerbating the spread of this plant beyond the sub-tropical range that it had previously occupied.

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Currently, the presence of P. stratoites is recorded in the northeastern region of the United States and in southern Ontario. This eventual migration northward has been recorded in “ponds connected to the Rideau Canal near Ottawa, and in the Welland Canal in the Niagara Region, Lake St. Clair and its tributaries, Bronte Creek in Oakville, and beaches east of Toronto” (OFAH/OMNR, 2012). In addition, its current distribution is also partially due to warming temperatures, and milder winters.

Since the P. stratiotes is not listed on the Invasive Species Act as a regulated or restricted plant, it is common for aquarium and pond stores to sell them. In fact, according to a study conducted near Lake Erie and Lake Ontario, 20% of aquarium and pet stores carried P. stratiotes (Rixon et al, 2005). This contributes greatly to its current spread, as owners of ponds and aquariums may improperly dispose of the plants, which may end up in the Great Lakes or their watersheds. Listed as having an extensive invasion history, according to the Great Lakes Aquatic Nonindigenous Species Information System (GLANIS) water lettuce has a “moderate probability of establishment if introduced to the Great Lakes” (Baker, 2015).

Ecological Connections

As it is known that water lettuce forms dense mats within water ways, it has strong potential to clog them, making recreational activities such as swimming fishing and boating difficult. In areas where water lettuce have formed these large mats, it also blocks out sunlight and in turn, reduces the amount of dissolved oxygen within the water. This makes it very difficult for other aquatic species to survive, especially since this plant is known to consume high quantities of nutrients from the water that it floats on. Not only do these large colonies make habitat less suitable for organisms which occupy the aquatic landscape, but they also block access to water for terrestrial animals (Baker, 2015). To add to this, P. stratiotes colonies can reduce water temperatures, reduce pH, and reduce oxygen mixing with surface wind. As a result, due to these limiting factors, P. stratiotes has the ability to kill native plants, fish and other wildlife in the area that it occupies (Attionu, 1976).

Critical Assessment of Management Options

There are several management strategies already put in place for dealing with non-native water lettuce in ecosystems around the world. Such strategies include the physical removal of the plants from their environment, utilizing other organisms who feed on this plant in order to eradicate it, chemically managing the species population through the use herbicides and cultivating the invasive species for commercial use. The success of these methods are all dependent on the particular location of the habitat, and other limiting factors such as accessibility and sensibility of the ecosystem. Figure 3 demonstrates a condensed version of the benefits and drawback of each strategy. The following is a descriptive list of the possible management strategies:

Chemical Control

The use of herbicide is certainly an effective way to eradicate floating plant matter, although since we are dealing with an aquatic ecosystem, the targeted species may not be the only one affected. Common herbicides such as Glyphosate and Diquat can cause massive weed die-off where the subsequent decomposition may end up removing much of the dissolved oxygen from the water (Baker, 2015).

Biological Control

There has been research conducted to determine if biological controls such as specialist herbivores, meaning organisms who require specific habitat requirement, can be used to eradicate or at least lessen population numbers of P. stratiotes. Species such as the water lettuce moth and the water lettuce weevil feet uniquely on this one plant, and have been used to control this plant in areas where it was not native (Cilliers, 1991). Within 12-18 months the South American water lettuce weevil was able to eradicate at least 40% of the water lettuce in Australia, where it was introduced (Harley et al., 1990). The issue with this approach is that introducing foreign species to a new environment has potentially disastrous consequences. It is very difficult to predict how a non-native species will interact with a new environment. This may not be the best approach for controlling water lettuce in southern Ontario.

Physical Control

To put it simply, this involves the physical removal of the floating plant from the ecosystem. This can be dealt with on a smaller scale by using a small boat, a rake and a bucket to collect the plants, or on a larger scale, through the use of mechanical harvesters. This generally makes for an effective management strategy, as it is a relatively non-invasive procedure concerning the health of the ecosystem. A concern with this method is that since removal boats will be passing through water lettuce patches, there is a risk that these vessels may serve as vector for seeds to “hitchhike” on, thus spreading to other locations.

The following video is a demonstration of how easy it is to conduct physical removals of water lettuce and water hyacinth in London, Ontario, at the Westminster pond. The Upper Thames River Conservation Authority monitors local water bodies for invasive species and

Physical Control with an Economical approach

If these plants can be harvested effectively, its nutritional and medicinal benefits could be put towards good use. Water lettuce contain high concentrations of protein, carbohydrates and fiber and is known to have anti-fungal and anti-microbial properties.  If there is no interest in the food or natural medicine market, they can be used to feed livestock as the plant is known to be fed to pigs. There has also been research into the use of this plant as bio-fuel in areas where water lettuce has overwhelmed certain river systems (Mishima et al. 2008).

Table 3. Management methods and evaluations for  Water Lettuce

Management Method Direct Costs Benefits Drawbacks Efficacy
No Action N/A N/A Continued spread and nuisance.  —
Chemical Control $$ Efficient eradication of species. Contamination, and reduced water and soil quality. May be costly if there is a need for remediation. +/–
Biological Control $ Efficient eradication of species at a low cost Unpredictability of the newly introduced species +/–
Physical Control $$$ Quick, efficient and effective. May spread the species to other locations. Costly. +/-
Physical Control with an Economic Approach $$ Quick, efficient and effective. Economic gain from species removal May spread the species to other locations. ++/-

 

Management Plan

This management plan provides detailed information regarding the most effective management option that involves the least risk to the environment and the general population. Based on the benefits outweighing the costs, it is determined that the physical removal of the plant is the most effective option for control, as long as a small, but closed, market can be built around the removal of the water lettuce. In this case, a closed market is a market in which profit is solely made for the progress of the management strategy.  This approach is the most viable method, since as much of the removed water lettuce can be sold as feed for livestock like cows and pigs, or even be used as a biofuel (Mishima, 2008) additive. Money generated from the sales of this plant can be used as a way to provide more funding towards management resources such as labour and equipment. This system does not create an increasing demand for the product, and would therefore does not necessarily create another market for the plant. If the plant was sold for potential medicinal properties after it’s harvested from targeted sites, there could possibility be an increase in demand for the product and would therefore contribute to the spread of water lettuce in southern Ontario. Previously, in Ontario (Azan, 2015) and in the southern United States (Langand, 1998), the physical approach has been implemented and seems to be the main tactic used my organization in North America.

In addition o this approach, the issue must also be addressed from a different angle. Not only does water lettuce need to be removed from bodies of water in southern Ontario, but the driving factor for its introduction to water ways must be diminished. Seeing that water lettuce is most commonly introduced to the natural environment via decorative ponds or aquariums, a public education plan must be set in place in order to engage communities in the prevention of its propagation and to encourage pond and aquarium business’ to stop selling water lettuce. Programs such as volunteer based river clean-up or invasive species bio-blitzes could be organized in partnership with organizations such as the OFAH of Ducks Unlimited. To add to these programs, pubic education nights and conferences can be hosted, along with efforts to build public pressure upon local governments to take action against the newly emerging invasive species. Strong social media can also reach many targeted interest groups across a broad platform.

Legal Factors

There are no laws conflicting with the physical removal of the invasive species, as it does not negatively impact the quality of the water that the invasive species resides in. Though in order to put more pressure on local and provincial governments to take action, the Clean Water Act (S.O. 2006, Chapter22) can be used as a stepping-stone towards involving communities in the management project. This act requires communities to monitor existing and possible threats to waterways, and to implement necessary actions to diminish the threat. It allows for public participation on all levels, in order for everyone to get the opportunity to play a role in the planning process of any mitigation or prevention plan against the invasion of water lettuce for example. Finally, and most importantly, the Clean Water Act of Ontario requires that all plans and projects must be “based on sound science” (Clean Water Act, 2006). In turn, the Provincial government of Ontario will have more reason to add water lettuce to the Invasive Species Act’s list of invasive species.

Potential Challenges and Solutions

Even if this management project may seem simple and small in scale compared to other efforts focusing on more prominent invasive species, such as giant hogweed and asian carp, this plan still faces many challenges. Most importantly, the issue of funding poses as the largest hurdle in this project. Without any form of income or outside support, no action can be taken against the spread of water lettuce in the waterways of southern Ontario. Secondly, industry that supplies water lettuce is to root cause of its current spread throughout natural water bodies in our region. Actions must be put in place in order to limit the sale of, or at least discourage these industries from selling water lettuce. Finally, in order to highlight the importance of the current issue facing water lettuce in southern Ontario, public knowledge and education programs must be put in place. This will prove to be one of the most important factors that will allow us to reduce the dispersal of the invasive aquatic plant. The following graph highlights the issues, their challenges and the potential solutions that are suggested in order to effectively coordinate a management strategy against the spread of water lettuce.

Table 3. Funding, public awareness of the issue and the water lettuce industry are the most prominent issues facing the management of water lettuce in Ontario.

Issues Challenges Solutions
Funding The challenge is finding the funding to pay for labour, equipment and other necessary resources required for managing the invasive species. -Selling collected water lettuce as biofuel or even as live stock feed.

-Running volunteer and community based programs in order to deal with the issue in a cost effective manner.

-Gain support from local government, in order to receive funding.

-Apply for grants.

The Water Lettuce Industry The decorative pond and aquarium industry is largely the reason whywater lettuce has spread so much in southern Ontario. The sale of this plant is not under any form of control. -Educate the general public about the issue.

– Social pressure from communities for stores to halt the sale of water lettuce may be effective on the small scale.

-Lobbying to add the plant on the Prohibited List of the Invasive Species Act would have the largest impact.

Lack of Public Knowledge Reaching out to a broad range of individuals may prove difficult. Engaging communities may be even more difficult to accomplish -Hold conferences

-Organize shoreline clean-ups and bioblitzes

-Develop a strong media presence.

-Develop partnerships with organizations such as Ducks unlimited or OFAH.

 

 

Conclusion

The physical removal of water lettuce paired with the establishment of a public education program is the ideal method for addressing the spread of water lettuce. This multi-faceted approach tackles the current issues that water ways in Southern Ontario face in regards to water lettuce, and also addresses the main source of the spread of the plant. Since this plan involves sound scientific research, community involvement and sound ecological practices, this management plan will ideally be successful upon its undertaking.

 

References

Attionu, R.H. (1976). Some effects of waters lettuce (Pistia stratiotes, L.) on its habitat. Hydrobiologia 50(3): 245-254.

Baker, H. (2015, February 2). NOAA National Center for Research on Aquatic Invasive Species (NCRAIS). Retrieved February 18, 2017, from https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?SpeciesID=15&Potential=Y&Type=2&HUCNumber=

Batcher, M. (2000). Element stewardship abstract for Eichornia Crassipes. The Nature                      Conservancy.

Castello, L. (2010). Participatory Conservation and Local Knowledge in the Amazon. The Amazon Varzea. 259-273.

Chace, T. (2013). Eradicate Invasive Plants. Timber Press.

CLOC. (2015). Central Lake Ontario Conservation. Invasive Wetland Species – Water Hyacinth. http://www.cloca.com/lwc/wetlands_invasive.php

Cilliers, C.J. (1991). Biological control of water lettuce, Pistia stratiotes (Araceae), in South Africa. Agriculture, Ecosystems, and Environment 37(1-3): 225-229.

Day J, Bianchi T, et al. (2003). Water Hyacinth Origins. Gulf Of Mexico Origin, Waters, and Biota : Volume 4, Ecosystem-Based Management. 83-88. College Station: Texas A&M University Press.

Evans, J.M. 2013. Pistia stratiotes L. in the Florida Peninsula: biogeographic evidence     and conservation implications of native tenure for an ‘invasive’ aquatic plant.     Conservation and Society 11(3):233-246.

Giammarco, T. (2004). Water Lettuce & Growth. Aqualand Factsheets.

http://aqualandpetsplus.com/Pond,%20Water%20Lettuce.htm

Gichuki, J., 2010. Does water hyacinth on East African lakes promote cholera outbreaks? American Journal of Tropical Medicine and Hygiene 83: 370–373.

Harley, K.L.S., R.C. Kassulke, D.P.A. Sands, and M.D. Day. (1990). Biological control of water lettuce, Pistia stratiotes (Araceae) by Neohydronomus affinis (Coleoptera: Curculionidae). Entomophaga 35(3): 363-374.

Kaufman, S.R. (2007). Invasive Plants: Guide to Identification and the Impacts of             Control of Common North America Species. Stackpole Books.

Langeland, K.A., and K.C. Burks. 1998. Identification and biology of non-native plants in Florida’s natural areas, p. 20. University of Florida. Gainesville, FL.

Mishima, D., M. Kuniki, K. Sei, S. Soda, M. Ike, and M. Fujita. (2008). Ethanol production from candidate energy crops: Water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes L.). Bioresource Technology 99: 2495-2500.

Richardson, J (2003). Weevils save lakes from water hyacinth pest. Ecological Economics, 45 (105-106). https://www.newscientist.com/article/dn3703-weevils-save-lakes-from-water-hyacinth-pest/

Rixon, C.A.M., I.C. Duggan, N.M.N. Bergeron, A. Ricciardi, and H.J. MacIsaac. 2005. Invasion risks posed by the aquarium trade and live fish markets on the Laurentian Great Lakes. Biodiversity and Conservation 14: 1365-1381.

OFAH/OMNR Invading Species Awareness Program. (2012). Water Lettuce. Retrieved from: http://www.invadingspecies.com.

Oyani, H. (2013). Water Hyacinth. Encyclopedia of Life. Podcast.

http://www.eol.org/collections/53846

Washington. (2014). Non-Native Freshwater Plants. Water Hyacinth.

http://www.ecy.wa.gov/programs/wq/plants/weeds/hyacinth.html

Attionu, R.H. (1976). Some effects of waters lettuce (Pistia stratiotes, L.) on its habitat. Hydrobiologia                50(3): 245-254.

Azan, S., Bardecki, M., & Laursen, A. E. (2015). Invasive aquatic plants in the aquarium and ornamental              pond industries: a risk assessment for southern Ontario ( Canada). Weed Research55(3), 249-          259. doi:10.1111/wre.12135

Baker, H. (2015, February 2). NOAA National Center for Research on Aquatic Invasive Species (NCRAIS).           Retrieved February 18, 2017, from               https://nas.er.usgs.gov/queries/greatlakes/FactSheet.aspx?SpeciesID=15&Potential=Y&Type=2      &HUCNumber=

Cilliers, C.J. (1991). Biological control of water lettuce, Pistia stratiotes (Araceae), in South Africa.          Agriculture, Ecosystems, and Environment 37(1-3): 225-229.

DMCA Complaint. (n.d.). Retrieved January 27, 2017, from        http://www.varsitytutors.com/act_science_28-problem-32660

EDDMapS. 2017. Early Detection & Distribution Mapping System. The University of Georgia – Center for            Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last      accessed January 26, 2017.

Harley, K.L.S., R.C. Kassulke, D.P.A. Sands, and M.D. Day. (1990). Biological control of water     lettuce, Pistia stratiotes (Araceae) by Neohydronomus affinis (Coleoptera: Curculionidae).   Entomophaga 35(3): 363-374.

Langeland, K.A., and K.C. Burks. 1998. Identification and biology of non-native plants in Florida’s natural           areas, p. 20. University of Florida. Gainesville, FL.

Mishima, D., M. Kuniki, K. Sei, S. Soda, M. Ike, and M. Fujita. (2008). Ethanol production from candidate           energy crops: Water hyacinth (Eichhornia crassipes) and water lettuce (Pistia stratiotes L.). Bioresource Technology 99: 2495-2500.

OFAH/OMNR Invading Species Awareness Program. (2012). Water Lettuce. Retrieved                 from: http://www.invadingspecies.com.

Pagnucco, K. S., Maynard, G. A., Fera, S. A., Yan, N. D., Nalepa, T. F., & Ricciardi, A. (2015). The future of           species invasions in the Great Lakes-St. Lawrence River basin. Journal Of Great Lakes Research,            41(Supplement 1), 96-107. doi:10.1016/j.jglr.2014.11.004

Pistia stratoites (water lettuce). (2015). Retrieved January 27, 2017, from          http://www.cabi.org/isc/datasheet/41496

Rixon, C.A.M., I.C. Duggan, N.M.N. Bergeron, A. Ricciardi, and H.J. MacIsaac. 2005. Invasion risks posed            by the aquarium trade and live fish markets on the Laurentian Great Lakes. Biodiversity and Conservation 14: 1365-1381.

Rivers L, 2002. Water Lettuce (Pistia stratoites). Gainsville, USA: University of Florida and Sea Grant.

Sculthorpe CD, 1971. The Biology of Aquatic Vascular Plants. London, UK: Edward Arnold Publishers.

Wang, X., Shi, L., Lan, C. Q., Delatolla, R., & Zhang, Z. (2013). Potential of water hyacinth for     phytoremediation in low temperature environment. Environmental Progress & Sustainable       Energy, 32(4), 976-981. doi:10.1002/ep.11853

English Ivy (Hedera helix), Lily of the Valley (Convallaria majalis), Goutweed (Aegopodium podagraria) and Periwinkle (Vinca minor)-Historical Profile

By: Christopher Aultman, Dylan Henry, Charlotte Leivo

History:

The following paragraphs will go into detail about the early records, uses and likely reason that contributed to the popularity and naturalization of the following groundcover species: English Ivy (Hedera helix), Lily of the Valley (Convallaria majalis), Goutweed (Aegopodium podagraria) and Periwinkle (Vinca minor).

English Ivy, Hedera helix, has been widely used by early Europeans as an insulator on stone buildings throughout the year (Sternberg, Viles, Cathersides, & Edwards, 2010). This may have had a large impact on English Ivy being imported to North America, with early records placing the plant in Virginia by 1762 (Wells & Brown 2000). The plant later became widely used for aesthetic purposes instead of as an insulator with the change of heating systems and house design (Sternberg, Viles, Cathersides, & Edwards 2010). The horticulture industry utilized the appeal of this plant to sell and distribute the ivy across North America, with the American Ivy Society widely promoting it currently (Waggy, 2010). Despite the horticulture industry’s success with selling English Ivy, it is having a profoundly negative impact on the natural ecosystem. The ivy was used for erosion control in the 1900’s which may have contributed to the plant’s establishment in many areas across United States. Birds also contribute to the dispersal of the seeds (Waggy, 2010). These factors have likely contributed to the plant negatively impacting the forestry industry by disrupting the growth patterns of the forest, which indirectly impacts the local distribution of the animal species (Waggy, 2010).

Lily of the Valley, Convallaria majalis, has been widely depicted in ancient lore with associations to the Virgin Mary being called Our Lady’s Tears and the virgin goddess of Ostara in Germany when they were pagans. (World of flowering plants, 2014) The plant was further used in a wine concoction to treat various ailments leading to the liquid being known as “Golden Water”. (Haas, N.D) These deeply rooted legends and uses in the culture of early Europeans may have lead to the plant being widely cultivated in North America. The American Gardening book indicates that Lily of the Valley was exclusively imported from Germany in the 1800’s. (Bailey, 1894) As time progress the plant was recommended to be planted for numerous hardy conditions where no other exotic plants would survive. (Bailey, 1894) This plant then escaped cultivation, becoming naturalized in native ecosystem and having the same effect on the landscape as the other groundcovers.

Goutweed, Aegopodium podagraria, was brought over by colonial settlers to America with early records placing it in North America since the 1850’s. (Waggy, 2010) Historically, goutweed was used for food and for its medicinal properties in treating gout, in many European countries, this was likely the reason behind bring the plant to North America. (Waggy, 2010) Goutweed is now being grown as an ornamental groundcover because of its rapid growth rate and hardiness in many environments. Nurseries throughout North America have widely promoted the plant for this use. (Waggy, 2010) As people became more irritated with the plant outcompeting the other plants in the garden people have disposed of the plant in various forests to be rid of the plant. (Waggy, 2010) This is now creating problems for the overall health of ecosystems and is getting the attention of the forestry industry and other natural groups.

Like goutweed, periwinkle was likely brought over initially for its edibility by early European settlers. Early records indicate that periwinkle has been in Virginia since 1771(Wells & Brown, 2000)  but may have been in North America earlier than this. The range of periwinkle is due to the horticulture industry, in the American Gardening book periwinkle was recommended on numerous accounts to be used for erosion control along the riparian zone (Bailey, 1894). This could have impacted the naturalization of the plant in native ecosystems in North America. As time progressed the plant was widely distributed and sold in many greenhouses and nurseries in North America for its gorgeous blue flowers and tolerance for shade (Stone, 2009). It is likely that periwinkle escaped cultivation from homes that bordered forested ecosystems (Darcy & Burkart, 2002), bringing rise to problems in the environment.

Ecological Connections:

The reproductive strategies deployed by the following groundcovers; Goutweed, Lily of the Valley, English Ivy, and Periwinkle have contributed to the successful establishment of the natural environment. Once in an ecosystem the rapid expansion by vegetative growth allowed the groundcovers to quickly form dense mats on the forest floor. This resulted in outcompeting native plant species and restricting available sunlight  that killed germinating native flora, including tree species (Waggy, 2010. Stone, 2009. Darcy & Burkart, 2002). The ability of English Ivy to grow vertically on trees and the use of adventitious roots allows it to create what is known as “Ivy deserts” in a forest as it affects all strata of a forest (Waggy, 2010). The rhizomes of goutweed and lily of the valley allow them to grow in numerous soil and shade conditions. Where then creep inward to areas that their seeds cannot properly germinate. The strong fragrances of these two groundcovers have been known to attract numerous pollinators to their flowers (Waggy, 2010. Ohara, Araki, Yamada, Kawano, 2006).

Other factors that possibly lead to these plants becoming established in an Ecosystem would be disturbed ecosystems. These ecosystems could have become disturbed by different factors. Overabundance of deer within an ecosystem results in the deer over browsing the native flora, which would lead to an open space where these invasive plant species can enter the area (Rawinski, 2008). Once these plants establish they quickly grow out of control unopposed because the deer do not favour these exotic plants. Other factors could be recent fires that disrupted the ecosystem or improper human management of the forest stands.

The negative impacts that the groundcovers have on a forest has recently started to raise concerns with environmental-related organizations and naturalist alike as they are decreasing the biodiversity in these forest ecosystems. As the formation of dense mats on the forest floor are affecting the forest’s ability to replenish varying levels in the canopy layer, weakening the overall health of the forest (Waggy, 2010). The biggest concerns for this comes from Periwinkle and English Ivy based on studies that confirmed they had an incredibly negative effect on the germination and growth of seedlings (Waggy, 2010. Darcy and Burkart, 2002). The high fragrance of goutweed and lily of the valley has gotten naturalists concerned about the pollinator to native plant species interaction, which may lower the seed reproduction of wanted native plant species (Waggy, 2010. Ohara, Araki, Yamada, & Kawano, 2006). Periwinkle, English Ivy and Goutweed have been known to negatively impact riparian zones and floodplains as they widely establish themselves in these areas or were once used as erosion control in these locations (Waggy, 2010). Furthermore, as native plants species begin to disappear in regions native fauna will begin to decrease in areas where these ground covers are taking over the forests.

Critical Assessment of Current Management Strategies:

Introduced invasive plants threaten ecosystems due to their excessive growth and have both ecological and economic impacts. Invasive species threaten native wildlife and ecosystems and are causing ecological havoc in many of our most sensitive habitats, pushing many of our native plants and animals to the brink of extinction (Padullés & Vila & Barriocanal, 2015). Each method option is described in the next paragraphs.

Prevention:

The best way to ultimately control these groundcover species is prevention. This can be achieved by maintaining a healthy ecosystem where these plants cannot establish themselves in. Other methods of preventing these species from invading these natural spaces is to educate the public on ways to ensure the plant cannot spread into these ecosystems. Like not planting these plants on areas that border the ecosystem where they could spread vegetatively or creating deep barriers that the roots would not be able to grow past.However, if the plants have already established themselves in these regions there are the following methods of control: Do nothing, Biological Control, Chemical Control, Mechanical or Physical Control. The following paragraphs will go into detail for the effectiveness of each control for English Ivy, Goutweed, Lily of the Valley, and Periwinkle.

Do Nothing:

Doing nothing is always an approach that can be taken to address this issue. Many people have voiced their opinion on the severity of invasive species establishing themselves in an environment or if it’s just natural and these species are just becoming integrated in the environment. This suggests that if a long enough time passes these plant species will be adopted into the diet of native fauna as some evidence of White-tailed Deer and Volcano Rabbit browsing on Periwinkle (Stone, 2009) is already coming to light. English Ivy is another plant species that has been documented to be incorporated in White-tailed Deer diets (Waggy, 2010). Currently there is no known species that native species that consume lily of the valley or goutweed but it has been noted that many pollinator species are widely attracted to these species and aid in the pollination. However, if these plants are left alone to grow out of control it would completely disrupt many ecological functions in an environment as they spread quickly by rhizomes and will out-compete all layers of a forest by restricting light to tree seedlings or ground flora (Stone, 2003. Waggy, 2010). Several studies focusing on the effects of leaving certain study plots unchecked in Michigan, Illinois, Oregon, Sweden, Czech Republic and the Netherlands indicate that the plant populations exponentially in the environment if unopposed. Resulting in potential losses in the Forestry Industry as wood production in these areas begin to decline without the growth of new trees. Other similar industries that benefit from resources coming from these forest ecosystems may also be negatively impacted.

Biological Control:

Biological control is another control method that proves to be effective in multiple studies that took place in Europe and United States for Goutweed, English Ivy and Periwinkle. One common biological control method for these species are the use of livestock; cattle, goats and sheep to limit or eliminate these species from an environment. In Oregon, a study was performed to look at the effects of goat browsing on English Ivy in managed plots in a forest ecosystem. The study showed that high intensity, short duration browsing of the juvenile stages of English Ivy resulted in the decrease of plant cover to 23% in the 1st year of browsing, and to 4% plant cover in the following year (Ingham & Borman, 2010). A similar study has been performed in New Zealand but substituted with sheep instead of the goat that yielded similar results. Another study done in the Netherlands showed the effects of large cattle browsing in forest ecosystems of bramble and groundcovers. This study showed that the effects of cattle browse and trampling effects on the ecosystem resulted in English Ivy and Periwinkle to disappear in the plot by 2004 despite there being no significant difference in frequency between the ungrazed and grazed plot in 2002 (Van Uytvanck & Hoffman, 2009). A study that was conducted in the Czech Republic, examined the effects of cattle grazing on forb species at a grassland site, the site contained varying intensities of Goutweed. This study revealed that varying intensities of cattle grazing resulted in the vast decrease or disappearance of Goutweed present at the pasture plots (Pavlů, Hejcman, Pavlů, Gaisler, & Nežerková, 2006). Therefore indicating that livestock browsing of all three species can be executed in a forest ecosystem and be effective in managing these invasive groundcovers species, the exception being Lily of the Valley. The study based out of Oregon further indicated that goats could be used within urban parks. (Ingham & Borman, 2010) The management strategy utilizes the agricultural industry to control invasive species in an ecosystem indicating the combined benefits of providing food for livestock that may be used for producing dairy, food, and/or textile products. Making this method cost effective as there is a source of income coming in from the used animal species but could cause other problems as the may consume wanted native flora and could compact the soils depending on the animals used.

Chemical Control:

Chemical control methods may be one of the most commonly used management strategies for large populations of invasive plant species throughout Canada and the United States of America. A study was done in Oregon that indicated performing chemical control on English Ivy in the winter proved to be effective (Waggy, 2010). Further studies completed in New Zealand indicated that basal application after the mature plant was cut proved effective for a short duration (Griffiths, 2010). It has been noted that Goutweed and Periwinkle persist after the use of Glyphosates because of the vegetative growth response following the procedures and the deep rhizomes that likely were not affected by the spraying (Waggy, 2010. Stone, 2009). The same is true for Lily of the Valley because it contains deeply rooted rhizomes that escapes the chemicals (Kosinski, 2003). Therefore proving that the application of herbicides is only a short-term solution to a long-term problem.

physical and mechanical control:

The most common way that many conservation areas remove invasive ground cover like periwinkle and goutweed is by implementing physical and mechanical control methods to remove the plant body and roots (CVC, 2017). This method of removal is only effective if the entire root mass is removed due to rhizomes being able to rapidly recolonize in the soil. If the entire plant is not removed the plant will continues to grow new shoots (CVC, 2017). Excavation can be very affordable if completed  with volunteers and hand tools. However heavy machinery can be used which will increase cost but reduce the duration of the project. In some cases these methods are the only available control methods for invasive plant species that do not utilize chemicals, Lily of the Valley is one of these species. A study done in Poland, simulated the effects an animal would have if they were to consume Lily of the Valley on a yearly basis by continually mowing populations of the plant (Kosinski, 2003). This study was successful in showing that if Lily of the Valley was intensively mowed back and trampled upon, the plant will decrease in vegetative cover (Kosinski, 2003). However, some of these methods may not be effective in a forest ecosystem as it will provide an entry point for new invasive species or will make it so new species cannot regrow in the area this is dependant on the material used to smother the plant. Therefore, indicating that these methods are best used in conjunction of previously mention methods to effectively remove the species or strategies of replanting native plant species in the area immediately following these methods. This method is incredibly physically demanding and involves a lot of labour if done on a larger scale, thus being an ineffective of management due to the high resource need.

Table 1: Illustrates a comparison of doing nothing,biological control, fire management, physical and mechanical control, herbicides and prevention as a method to resolve the invasion of Vinca minor L., Convallaria majalis, Aegopodium podagraria & Hedera helix in North America.

Strategy Cost Benefits Factors Effectiveness
Do Nothing $ Cost Effective Would cost more to maintain landscape with the outspread of targeted species expanding.  Species would continue to thrive and choke out native plants.
Biological Control $$ Effective in natural removal and fertilizing of area. Consumes wanted native plant species. +
Physical and Mechanical Control $$-$$$$ Only targeted species are removed from the area. Can be cheap. Labour intensive. Soil compaction. Disturbed soils could provide suitable germination for other invasives +
Herbicides $$$ Effective initial short-term treatment Plants that are not targeted may also be affected by spray methods
Prevention $ Natural ecosystem restored. Effective in preventing plants initially but does not work if the invasive plants are already present. ++

References

Bailey, L.H. (1894) American Gardening: A Journal of Horticulture. 1893-1894 (Vol. 15). New York, NY: A. T. De La Mare PTG. & PUB. CO., Ltd.

Darcy, A.J., & Burkart, M.C. (2002). Allelopathic Potential of Vinca minor, an Invasive Exotic Plant in West Michigan Forests. Bios, 73(4), 127-132. Retrieved from http://www.jstor.org/stable/4608646

Griffiths, K. (2010) Control methods of English Ivy in Puahanui Bush, NZ. The Conservation Company LTD. Retrieved from   http://www.theconservationcompany.co.nz/pdf/Control%20methods%20for%20English%20ivy.pdf

Haas, L.F. (N.D). Convallari majalis (lily of the valley) (also known as Our Lady’s tears, ladder to heaven).Journal of Neurology, Neurosurgery & Psychiatry 1995;59:367.

 

Ingham, C. S., & Borman, M. M. (2010). English Ivy (Hedera spp., Araliaceae) Response to Goat Browsing. Invasive Plant Science & Management, 3(2), 178-181. doi:10.1614/IPSM-09-021.1\

Kosinski, I. (2003) The Influence of Shoot Harvesting on the Age Structure of Convallaria majalis L. Populations. Acta Societatis Botanicorum Poloniae (Vol 72). No. 1: 53-59,2003

Ohara, M., Araki, K., Yamada, E., & Kawano, S. (2006). Life-history monographs of Japanese plants. 6: Convallaria keiskei Miq. (Convallariaceae). Plant Species Biology, 21(2), 119-126. doi:10.1111/j.1442-1984.2006.00157.x

Pavlů, V., Hejcman, M., Pavlů, L., Gaisler, J., & Nežerková, P. (2006). Effect of continuous grazing on forage quality, quantity and animal performance. Agriculture, Ecosystems And Environment, 113349-355. doi:10.1016/j.agee.2005.10.010

Padullés Cubino, J., Vila Subirós, J., & Barriocanal Lozano, C. (2015). Propagule pressure from invasive plant species in gardens in low-density suburban areas of the Costa Brava (Spain). Urban Forestry & Urban Greening, 14941-951. doi:10.1016/j.ufug.2015.09.002

Rawinski, T.J. (2008) Impacts of White-Tailed Deer Overabundance in Forest Ecosystems Overview. Forest Service, U.S. Department of Agriculture, Northeastern Area State and Private Forestry. (Producer). Retrieved from https://www.na.fs.fed.us/fhp/special_interests/white_tailed_deer.pdf

Sternberg, T., Viles, H., Cathersides, A., & Edwards, M. (2010). Dust particulate absorption by ivy (Hedera helix L) on historic walls in urban environments. Science Of The Total Environment, 409162-168. doi:10.1016/j.scitotenv.2010.09.022

Stone, K.R (2009) Vinca Major, V, Minor. In: Fire Effects Information System [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Retrieved from http://www.fs.fed.us/database/feis/plants/vines/vinspp/all.html

Vandepitte, K., De Meyer, T., Jacquemyn, H., Roldan-Ruiz, I., & Honnay, O. (2013). The Impact of extensive clonal growth on fine-scale matting patterns: a full paternity analysis of a lily-of-the-valley population (Convallaria majalis). Annals of Botany, 111(4), 623-628

Van Uytvanck, J., & Hoffman, M. (2009) Impact of grazing management with large herbivores on forest ground flora and bramble understory. Acta Oecologia, 35(4):523-532. DOI: 10.106/j.actao.2009.04.001

Waggy, M. A. (2010) Aegopodium podagraria. In: Fire Effects Information System. [Online.] U.S Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Retrieved from https://www.fs.fed.us/database/feis/plants/forb/aegpod/all.html

Waggy, M. A. (2010) Hedera helix. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [2017, February 11].

Wells, E., & Brown R.L. (2000). An Annotated Checklist of the Vascular Plants in the Forest at Historic Mount Vernon, Virginia: A Legacy from the Past. Castanea, 65(4), 242-257. Retrieved from http://www.jstor.org/stable/4034007

World of Flowering Plants (2014) Legends and Facts about the Lily of the Valley. (Online) Retrieved from http://worldoffloweringplants.com/legends-facts-lily-valley/

White-tailed Deer (Odocoileus virginianus) -Historical Profile

Written by: Sean Bryan, Jessie Harris, Narmeen Nweisser, Frank Zacharias.

Historical Profile
The white-tailed deer has been recorded to have originated near regions north of central Mexico (Morales, 2016) and has since made its way both south to northern parts of South America and into Canada and fading in population size as they reach the boreal zones of Canada. Ontario has not always been a suitable habitat due to glaciers covering the landscape leaving behind landforms such as moraines and eskers (Dawe, 2014)

The St Lawrence lowlands within Ontario and nearby Provinces is composed of rich ecosystems that are suitable for the survivorship of the white-tailed deer. This same area became home to Indigenous clans which historically may have followed the deer and other game animal’s north from parts of America or pushed there such as the Anishinabek (Warrick, 2012) who were designated land along the Grand River watershed in treaty agreements.  The Native Americans would make sure that almost nothing of the deer was wasted within the community. They would eat the meat and use bone marrow to make up a large part of their diet, but they would also use the hides for things like rugs, clothes, fishnets, and blankets. The antlers and bones would be crafted into arrowheads, clubs, fishhooks, and tools for the Indigenous people to use. This made the white-tailed deer sought after for both Indigenous and non-Indigenous peoples and also has become a trophy species, the trophy being the antlers on a male deer.

However with the settlement of farmers in North America it caused the deer populations to decline with the removal of cover for crops and unregulated shooting. As logging was happening for more land to be used for crops, more and more of the opposite effects on the deer populations occurred. Logging caused more openings, made more brush, and younger forests to establish making it the perfect condition for deer. This caused an estimate climb in the population of about a million deer. As railroads were introduced it made it easier to access the wilderness. With the population of deer rising and access to more wilderness, the amount of hunting that was done increased again. In 1895 Michigan began making progress on deer management in the state with making a deer hunting season and a limit amount that could be harvested. For decades after the laws were made there was a constant up and down in the populations due to the seasons for hunting to change new regulations and available habitat. In 1986 only Colorado, Massachusetts, New York, Oklahoma, and Texas reported over-populated deer ranges. In contrast, in 2013, 18 of 47 states surveyed reported issues with overpopulated deer herds in urban areas.In many states the deer population is at or below biological carrying capacity (K) but exceeds social carrying capacity. Many current issues with White-tailed deer are related to an increasingly urban human population that is less tolerant of deer, and not necessarily with increases in deer populations.” (Krausman,Christensen,Mcdonald, & Leopold, 2014). Today, the white-tailed deer is the most widespread deer in the world, making it the most popular game in the United States chased by about 11 million hunters. There is now problems that arise due to the adaptability of the deer. Since the deer are very adaptable it makes it easy for them to become a problem within an urban city. Deer sterilization is one way of controlling deer populations within a city.

 

Ecological Connections:

Eradicating of the white-tailed deer can be done but would take a long time too. This is because the white-tailed deer population is high. The deer is a “K” strategy species like described above, they have a long life span but take a lot of care to get to an older age, which makes them a slow growth population (Fulbright, 2013). This makes for easy eradication because you can wipe out a population quickly by hunting the deer and putting them under stress. In Ontario for example, deer populations in the city of London have been a concern for the last decade, especially the habitats associated with the Sifton Bog. Concerns include the natural areas within the city of London and how they are impacted by deer. (Stephenson,2011)

Deer are herbivores that graze on long grasses in the summer time. While deer are in the long grass they can have a Deer Tick attach to them (Safer, 2017). By having the deer in the city they may bring in the ticks that they could have gotten in the long grass into the city. This is a problem because these ticks can be transmitted to your dogs and causing death, but also humans as well through Lyme disease. The challenges cities have been facing is trying to find the balance of the number of deer to the homeowners and their properties (Safer, 2017). Okay but you should be mentioning that Lyme Disease is the cause of issues which is transmitted by the ticks.

In Manitoba there is currently over 6,000 deer-vehicle collisions every year, making it a problem to humans (n.a., 2010). The deer’s habitat is along forest edges and if you put a road through a forest there is a good possibility that they will need to cross the road is high. Deer are also obligate migrators, meaning they must travel to find food. This can relate to deer collisions because if they need to cross a road to get to another source of food that increase the chances of collisions on the roads. Vehicle damage can also be costly to the car owners. There is also a problem with deer eating farmers crops and damaging resident’s landscape of their yard. (n.a.,2010). For these reasons the deer population needs to decrease around urban cities without causing a lot of damage to the ecosystem.  Another factor is the overgrazing of forests and fields near or in urban areas.  The lack of space and over abundance of white-tailed deer lead them to over graze causing a negative effect on ecosystems.

 

Critical Assessment of Management Options

For the population of white-tailed deer to be controlled around an urban city there are various methods of control without damaging the ecosystem and the species. Sterilization of the doe’s is an effective way to control urban deer populations. Opening the hunting season for a wider range throughout the year can help control populations. Using fence to keep the deer away from roads and urban places is also another option for controlling the deer.  Relocation of white-tailed deer is also an option but is rarely feasible because lots of variables fall into place, such as high costs, lack of habitat to relocate to, high stress on the individual deer and high mortality rate.  (Boulanger, 2012). The option to do nothing is always something ecologists need to keep in mind and always looking at the history to make sure they weigh out all options before making one.

A method that is used by some cities is to sterilize the female deer (doe). Sterilization is an effective method to help reduce deer populations around urban settings. Sterilizing the females will reduce the amount that a deer can reproduce causing a decline in cities. This method however is very labour intensive making it one of the most expensive ways of dealing with the problem. It takes many hours to set up traps for the deer as well as doing the surgery on the deer. The multiple people that would be working on this project would need to have a high level of training/expertise, making them a high paid employee. Doing the surgeries on the deer it will also cost a lot in tools transportation and traps (Schwantje, 2015). Surgical sterilization is the most dependable means to permanently sterilize female deer. Sterilization of a bigger population of female deer has the advantage of lessening deer numbers more quickly and producing fawns overall. (Grovenburg,2009). Although this method of controlling the population will work it is very costly. (Cornell)

Another way to reduce the population of deer around an urban area is to open the hunting season for a longer duration. Having the hunting season expanded can be a very effective way to reduce numbers. Hunting can also have a positive impact on the community by having a cultural practice and being able to do so for a longer period of time in the year. By hunting, the hunters get to use the meat for consumption for themselves, family and friends. These two factors can help a community greatly. This method has very minimal cost to the government for the decrease in the population because they do not need to hire employees to do the work (Schwantje, 2015). Customary strategies for overseeing overabundant white-tailed deer concentrate on lethal removal, for example, hunting or sharp shooting. Although it has been proposed that culling may be the most practical alternative. Lethal control might be unreasonable in a few communities because of legal, well-being or moral concerns. (Grovenburg, 2009). Also the hunting would be happening outside of the urban areas which may actually make the deer come to the city for more cover where they cannot be killed.

Table 1. Illustrates a comparison of the management methods to determine what method to use for the management of the white-tailed deer.

Management Method Costs Benefits Factors Efficacy
Hunting/Sharpshooting Make money on tags Reducing/maintaining populations in large areas Safety concern
Most effective currently
 +
Deer Contraception/Sterilization Expensive Maintaining populations  Labour intensive  –
Do Nothing Nothing Wouldn’t be harmed from human, just predators, accident collisions Not managing pop. will make healthy forest unsustainable  –
Rehabilitation Expensive

References
Ambriz-Morales, P., De La Rosa-Reyna, X. F., Sifuentes-Rincon, A. M., Parra-Bracamonte, G.M., Villa-Melchor, A., Chassin-Noria, O., & Arellano-Vera, W. (2016). The complete mitochondrial genomes of nine white-tailed deer subspecies and their genomic differences. Journal Of Mammalogy, 97(1), 234-245. doi:10.1093/jmammal/gyv172

Dawe, K., Bayne, E., & Boutin, S. (2014). Influence of climate and human land use on the distribution of white-tailed deer (Odocoileus virginianus) in the western boreal forest. Canadian Journal Of Zoology, 92(4), 353-363.

Donovan, J. (June 4, 2013). Science News. White-tailed deer and the science of yellow snow.

Entomological Society of America. (2014, July 1). Reducing deer populations may reduce risk of Lyme disease. ScienceDaily. Retrieved February 3, 2017 from http://www.sciencedaily.com/releases/2014/07/140701111549.htm

Feltham, J. V. (2017, January 20). Jfeltham_ecological_profile. Lecture presented at Species Management in Fleming Campus, Lindsay.

Fieberg, J., Kuehn, D. W., & Delgiudice, G. D. (2008). Understanding Variation In Autumn Migration Of Northern White-Tailed Deer By Long-Term Study. Journal Of Mammalogy, 89(6), 1529-1539.

Georgia, U. o. (September 28, 2015). Be on the lookout this fall: Deer-vehicle collisions increase during breeding season. Science News.

Grovenburg, T. W., Jenks, J. A., Klaver, R. W., Swanson, C. C., Jacques, C. N., & Todey, D.(2009). Seasonal movement and home ranges of white-tailed deer in north-central South Dakota. Canadian Journal Of Zoology, 87(10), 876-885.

Hewitt, David G. (2011). Biology & Management of White-tailed Deer. Taylor & Francis.

Hummel, S. ‘., Campa, H. I., Locher, A., & Winterstein, S. R. (2016). Spatial quantification of white-tailed deer habitat of a wetland-dominated landscape in Central Lower Michigan. Michigan Academician, (3), 393.

Klaver, R. W., Jenks, J. A., Deperno, C. S., & Griffin, S. L. (2008). Associating Seasonal Range Characteristics With Survival of Female White-Tailed Deer. Journal Of Wildlife Management, 72(2), 343-353. doi:10.2192/2005-581

Krausman, P. R., Christensen, S. A., McDonald, J. E., & Leupold, B. D. (2014). Dynamics and social issues of overpopulated deer ranges in the United States: a long term assessment. California Fish & Game, 100(3), 436-450. Retrieved from                                                               http://www.bcqwc.org/uploads/5/0/9/9/50992449/krausman_et_al_2014.pdf

Stephenson, D., Dance, K., Anderson, P., Brenton, T., Murphy, S., Smith, D., Boles, R.,Keable, L. (2011) Sifton Bog White-Tailed Deer Management Study City of  London.[PDF file] Retrieved from http://thamesriver.on.ca/wp-content/uploads/WestminsterPonds/Report-DRAFT-Sifton-DeerManagement-January11.pdf

Warrick, G. (2012). Buried Stories: Archaeology and Aboriginal Peoples of the Grand River, Ontario. Journal Of Canadian Studies, 46(2), 153-177.

 

 

 

 

 

 

 

Coyote (Canis latrans)- Ecological Profile

Written By: Madison Penton, Emma Ross, Adam Bocskei & Jesse Beauchamp

Distribution: The coyote, Canis latrans, is a North American based species which is part of the family Canidae. Coyotes can be found country-wide in the United States and Mexico. While in Canada the majority of the distribution of this animal tends to be in the west side of the country as far north as the Northwest Territories (including Alaska) and as far east as the southern part of Saskatchewan, Manitoba and Ontario (Churcher, 2012). Figure 1, demonstrates the global distribution of the Canis latrans while, Figure 2 illustrates the Ontario wide distribution of this canid.  Coyotes are not found in the northern part of Ontario, but their family member the gray wolf, Canis lupus  is present there (IUCN (International Union for Conservation of Nature), 2008).

globalmap

Figure 1: The Coyote is found primarily in North America but is now being found as far south as Panama. (Emma Ross, ArcMap 10.4. Modified from Basemap ESRI 2015, Dark grey)

capture
Figure 2: The Coyote is found primarily in North America but is now being found as far south as Panama. (Emma Ross, ArcMap 10.4. Modified from Basemap ESRI 2015, Dark grey)

Habitat: It is predicted that coyotes originated from open habitats in west-central North America and were able to expand their range due to forestry, agricultural development, and the eradication of wolves (Chubbs, Phillips, 2005). Although coyotes can live in forested areas, forests are not considered to be ideal habitats due to the coyotes poor hunting abilities in dense vegetation (Hidalgo-Mihart, Cantú-Salazar, López-González, Martínez-Gutíerrez, 2006). It is thought that habitat selection by coyotes may be influenced by the availability of water in arid sites such as prairies, but also as on moist sites such as riparian zones (Poessel, Gese, Young, 2017). Like many Canidae species, coyotes hold territories to ensure optimal reproductive fitness through group living, and to sustain access to food, space, and cover (Cese, 2001; Bekoff, Diamond, Mitton, 1981). Coyotes are well known for their adaptability and use of urban environments. Coyote populations can even respond positively to urban environments. In southern California, a study conducted by Ordeñana, et al. (2010), showed that coyote occurrence increased with both proximity and intensity of urbanization. Individual coyotes may be classified in their social organization as residents or transients. Transient coyotes do not maintain territories and exhibit nomadic movements with no fidelity for any one area (Hinton, van Manen, Chamberlain, 2015).

Coyote Cuddle
Figure 3: Picture of two coyote pups cuddling. Photo taken near Stony Plain, Alberta Source: http://harveywildlifephotography.ca/

Potential For Infestation: A study conducted by Carlson et al. (2008) suggests that female coyotes only reach estrus once per year. They are socially r-strat_animal_yellowmonogamous as well as territorial and once they are bonded with a male coyote, the pair remains together for a number of years. During this time they have litters averaging 3-7 pups which are typically born between May and March after a 60-63 day gestation period. Pups reach sexual maturity as early as 10 months, but the majority begin producing litters at roughly 22 months. Placental scars show that fecundity is at its highest between 3 and 8 years (Carlson, D. A. et al., 2008).

Sacks (2005) states that the coyote has an unusually wide range of life history strategies due to their highly variable fecundity. The size of their litter and their survivorship depend heavily on food resources and stress levels. They have the ability to compensate for increased mortality through their adaptability and increased litter sizes. In situations where coyote mortality is high, they tend to reproduce at higher rates, resembling r-strategists. In situations where mortality is low they tend to reproduce at lower rates, resembling k-strategists (Sacks, 2005).

The reintroduction of gray wolves to Yellowstone National Park in 1995 proved to be an important opportunity for coyote research. According to the National Park Service (n.d.), coyote populations were reduced by as much as 50% within 3 years of the first wolf being reintroduced (see figure x). However, by 2007, coyote populations had recovered back to the levels previously observed before gray wolf reintroduction (National Park Service, n.d.). This is an example of the coyote’s ability to adapt quickly to stress through both behavioral changes and reproductive strategies.

popgraph

Figure 4: Coyote populations in Lamar Valley, Yellowstone National Park before, during, and after gray wolf reintroduction in 1995 (National Park Service, n.d.).

Survivorship:  Coyote survival rate is generally even throughout their life due to their ability to make use of a wide variety of food sources and the relatively low number of natural predators through most of their range. Windberg’s (1995) study indicates that coyotes age 1-2 can expect a survival rate of 0.56, while coyotes age 2-8 have the highest rate of survival at 0.69. Juvenile coyote survival (birth to following spring) ranged from 0.32 to .73 (Windberg 1995). This places coyote in the Type II Survivorship curve (see figure x).

survivourshipfinal

Figure 5: The figure depicts Type I, Type II, and Type III survivorship curves. Coyotes are unique in that they can fit into more than one curve, though they tend toward the Type III side of the Type II curve (Alpha Image, n.d).

Dispersal/ Vectors: Historically Coyotes, Canis latrans only existed in West- central Vector_HumanNorth America until the expansion of agricultural lands began. (Boisjoly, D., Ouellet, J., & Courtois, R., 2010).  Coyotes travel in packs by foot and their ranges are made up primarily of open lands but they can have ranges in many types of climates. Unlike their relative the Grey Wolf urban areas with high populations of humans don’t stop coyotes from moving through an area . Coyotes actually flourish in disturbed environments such as towns and cities because of the high food availability. Coyotes have also been seen traveling by roads and even using bridges to travel through developed areas (Hinton, J.W., van Manen, F.T., & Chamberlain, M.J., 2015)

Special Considerations: Coyotes have long been considered a nuisance to some livestock farmers. In the United States, coyotes are the largest victim of livestock predator control, constituting 75% – 95% of all large predators removed (Berger, 2006). Although control efforts are often successful in terms of the number of carnivores removed, the effects of predator removal on the success of the livestock farming are not fully understood (Berger, 2006). In one study conducted by Berger (2006) to examine the effectiveness of government subsidized predator control, he concluded that “From both an economic and a public policy perspective, taxpayer dollars might be better spent to support sheep producers through direct cash payments or some other form of subsidy if the goal is to increase sheep and wool production and not merely to kill carnivores.” Due to their adaptation to urban environments, coyotes are occasionally involved in conflicts with pets, and humans (Poessel, Gese, Young, 2017).

References

Alpha Image. (n.d). Survivorship Curves. Retrieved from      http://alfa-img.com/show/survivorship-curve-example.html

Bekoff, M., Diamond, J. & Mitton, J.B. (1981). Life-history patterns and sociality in   canids: Body        size, reproduction, and behavior. Oecologia September 1981,   Volume 50, Issue 3, pp        386–390

Berger, K. M. (2006). Carnivore-Livestock Conflicts: Effects of Subsidized Predator Control and        Economic Correlates on the Sheep Industry. Conservation Biology, 20(3), 751-761.         doi:10.1111/j.1523-1739.2006.00336.x

Boisjoly, D., Ouellet, J., &Courtois, R. (2010). Coyote Habitat Selection and Management             Implications for the Gaspésie Caribou. Journal Of Wildlife Management, 74(1), 3-11. doi:         10.2193/2008-149

Carlson, D. A., & Gese, E. M. (2008). Reproductive Biology of the Coyote (Canis Latrans): Integration of Mating Behavior, Reproductive Hormones, and Vaginal Cytology. Journal of Mammalogy, 89(3), 654-664. Retrieved from http://ra.ocls.ca/ra/login.aspx?inst=sandford&url=?url=http://search.proquest.com/docview221473118?accountid=28555

Chubbs,T.E., and Frank RP. (2005). Evidence of range expansion of eastern Coyotes, Canis latrans in Labrador. Canadian Field-Naturalist 119(3): 381-384.

Gilbert-Norton, L. B., Wilson, R. R., Shivik, J. A., & Zeh, D. (2013). The Effect of Social         Hierarchy on Captive Coyote (Canis latrans) Foraging Behavior. Ethology, 119(4),            335-343.doi:10.1111/eth.12070

Grady, W. (1995). The World of the Coyote. Vancouver : The Sierra Club.

Hidalgo-Mihart, M. G., Cantú-Salazar, L., López-González, C. A., & Martínez-Gutíerrez, P. G. (2006). Coyote Habitat Use in a Tropical Deciduous Forest of Western Mexico. Journal Of Wildlife Management, 70(1), 216-221.

Hilton, H. (1978). Systematics and Ecology of the Eastern Coyote. New York: Academic Press, Inc.

Hinton, J.W., van Manen, F.T., & Chamberlain, M.J. (2015). Space Use and Habitat Selection by  Resident and Transient Coyotes (Canis latrans). Plos ONE, 10(7), 1-17. Doi:10.1371/journal.pone.0132203

Magle, S., Simoni, L., Lehrer, E., & Brown, J. (2014). Urban predator-prey association: coyote        and deer distributions in the Chicago metropolitan area. Urban Ecosystems, 17(4),         875-891. doi:10.1007/s11252-014-0389-5

National Park Service. (n.d.). Coyote Information Continued. Retrieved from https://www.nps.gov/yell/learn/nature/coyoteinfo.htm

Ordenana, M. A., Crooks, K. R., Boydston, E. E., Fisher, R. N., Lyren, L. M., Siudyla, S.,      & …        Van Vuren, D. H. (2010). Effects of urbanization on carnivore species distribution and        richness. Journal Of Mammalogy, (6), 1322.

Poessel, S. A., Gese, E. M., & Young, J. K. (2017). Research paper: Environmental factors        influencing the occurrence of coyotes and conflicts in urban areas.  Landscape And        Urban Planning, 157259-269. doi:10.1016/j.landurbplan.2016.05.022

Rinehart, M. E. (2011). Behaviour of North American Mammals. New York: Houghton Mifflin        Harcourt Publishing Company.

Sacks, B. N. (2005). Reproduction and Body Condition of California Coyotes (Canis Latrans). Journal of Mammalogy, 86(5), 1036-1041. Retrieved fromhttp://ra.ocls.ca/ra/login.aspx?inst=sandford&url=?url=http://search.proquest.com/docview/221453698?accountid=28555

Swingen, M. B., DePerno, C. S., & Moorman, C. E. (2015). Seasonal Coyote Diet Composition at a Low- Productivity Site. Southeastern Naturalist, 14(2), 397-404.

Windberg L. A. (1995). Demography of High Density Coyote Population. Retrieved from https://www.aphis.usda.gov/wildlife_damage/nwrc/publications/95pubs/95-70.pdf

Young, J. K., Andelt, W. F., Terletzky, P. A., & Shivik, J. A. (2006). A comparison of coyote ecology     after 25 years: 1978 versus 2003. Canadian Journal Of Zoology, 84(4), 573-582.            doi:10.1139/Z06-030

English Ivy (Hedera helix), Lily of the Valley (Convallaria majalis), Goutweed (Aegopodium podagraria) and Periwinkle (Vinca minor)- Ecological Profile

Written By: Chris Aultman, Dylan Henry, Charlotte Leivo, Annika Young

There are four invasive groundcovers that are becoming an increasing concern in Canada and United States of America, for they are becoming better established within the natural environment: English Ivy (Hedera helix), Goutweed (Aegopodium podagraria), Lily of the Valley (Convallaria majalis), and Periwinkle (Vinca minor).

r-strat_plant_yellow

Distribution

Common invasive groundcover species are Periwinkle (Vinca minor) and Goutweed (Aegopodium podagraria) originate from Eurasia. The two plants now grow in Southern Canada from British Columbia to Southern Ontario, as well as the West coast and East United States. The global distribution of the two invasive plants can be found on Figure 1 and the distribution of the plants in Ontario can be found on figure 2.

Lily of the Valley, Convallaria majalis, originates from Europe and Eurasia (shown in Figure 3).  The species ranges from most States and some of Southern Canada (shown in Figure 2). They were brought to North America by settlers that used this plant for ornamental and medicinal purposes. It is highly toxic to animals, particularly the leaves and each plant has a different amount of toxin called convallatoxin. (Kaufman & Kaufman,2007).

English Ivy, Hedera helix, is an evergreen climbing plant native to Europe, western Asia, and northern Africa (Kaufman & Kaufman, 2007). English Ivy was introduced to North America as a decorative plant starting in the 1700s and is now considered an invasive species (Kaufman & Kaufman, 2007). It is found in 26 states in the United States, southern British Columbia, and southwestern Ontario and has also been introduced to South Africa, India, Australia, New Zealand, Brazil, and Mexico (Kaufman & Kaufman, 2007; Waggy, 2010).

Periwinkle Goutweed Global Distrabution
Figure 1: Global Distribution of Periwinkle (Vinca minor) and Goutweed (Aegopodium podagria) (ArcMap 10.4, EDDMaps 2017, iNaturalist 2017)
Ontario_Common_Invasive_Groundcover
Figure 2: Southern Ontario Distribution of the four Common Invasive Ground Covers, English Ivy (Hedra helix), Goutweed (Aegopodium podagraria), Lily of the Valley(Convallaria majalis), and Periwinkle (Vinca minor) (ArcMap 10.4, EDDMaps, 2017)
lilyofthevalley_global_dist
Figure 3: Global Distribution of Lily of the Valley (Convallaria majalis) (Modified by Invasive plants, 2017 Base map source: ArcMap 10.4)

Habitat

Periwinkle is often found in open forests and around old home-sites as they were favoured by early European settlers for their medicinal properties. (Kaufman, Kaufman. 2012) These

periwinkle

Figure 7: Common Periwinkle, Vinca minor (Zell, 2009 a)

plants can be found in soils that are: Silt loams, Clayey, loamy and sandy soils, and rocky sandy soils. (Stone. 2009) However, they prefer soils that are fertile and moist but can tolerate lowly fertile and moderately to well-drained soil site locations.(Stone, 2009) They further favour soils that are relatively shallow, 5.7-8.7 inches deep, and grow in soils of 5.7-7.2 PH levels. Periwinkle favours partial shade but is known to tolerate full sun and fully shaded areas. (Stone, 2009)

 

Goutweed is often found in moist sites, preferably sites that are moist and well drained within partial shade areas. (Waggy. 2010) These plants are tolerant of floodplains and

goutweed
Figure 8: Goutweed, Aegopodiom podagraria (Peters, 2005)

moisture contents that are 33.2-36.4%. Goutweed is known to be a nitrophilous species, meaning they are indicators of nitrogen rich soils but is more restricted by soil PH levels.
The PH levels they have been known to occur in is 3.1-9 within its native range in Europe. (Waggy, 2010)The soil they seem to prefer are: Sandy loam, silty loam, and sandy clay.
(Waggy, 2010) These species are highly tolerable of highly shaded area where the canopy layer is 90% and seem to prefer thin litter layers to spread. (Waggy, 2010)The areas they are known to first establish within are roadsides, forest edges and disturbed forest floors (Kaufman, Kaufman) before expanding vegetatively into areas that seed germination is not favourable.

Lily of the valley has adapted to grow in a wide range of soils that are acidic and alkaline.

lily_of_the_valley
Figure 9: Lily of the Valley, Convallaria majalis (Zell 2009 b)

(Vandepitte, De Meyer, Jacquemyn, Roldan-Ruiz, & Honnay, 2013)  However, is mainly found within acidic soils in its native range and its non-native range in North America. They thrive within fertile and humic soils (Kaufman, Kaufman) with well drained moist soils. (Vandepitte, De Meyer, Jacquemyn, Roldan-Ruiz, & Honnay) Within its native range it is mainly found in ancient deciduous forest and naturalizes within similar forest types around the world. Studies suggests that it can tolerate coniferous forested sites with highly acidic soils as well as low light conditions but does not perform well under these conditions. (Verstraeten, Baeten, De Frenne, Thomaes, Demey, Muys, & Verheyen. 2014) Further indicating that they can thrive within mix-forested, Carolinian and boreal forests in Canada.

 

The preferred habitat of English Ivy in its native range is floodplains with moist, nutrient-rich substrates (Schnitzler & Heuzé, 2006).

english_ivy
Figure 10: English Ivy, Hedera helix (Chery, 2006)

Its preferred hosts in this environment are large and isolated trees that provide greater surface area for attachment and increased exposure to sunlight (Castagneri, Garbarino, & Nola, 2013). In North America, English Ivy prefers moist areas with full to partial shade but can also tolerate drought (Kaufman & Kaufman, 2007). It has been noted to thrive in disturbed and fragmented forests (Kaufman & Kaufman, 2007; Londré & Schnitzer, 2006). English Ivy is capable of growing in Canadian Hardiness Zones 4a to 8b (Pascoe, 2017).

 

Reproductive Strategy

Organisms can generally be divided into two broad categories of reproductive strategy: r-selection and K-selection. R-strategists have high population growth rates and typically colonize new or disturbed areas, while K-strategists favour efficient use of resources and are typically found in areas where populations are near carrying capacity (Molles & Cahill, 2014). Most species of invasive plants would be expected to be r-strategists. However, despite its preference for colonizing disturbed areas, English Ivy displays two traits associated with K-strategists: longevity and parental investment. English Ivy can live for many decades. Schnitzler and Heuzé (2006) found a specimen in northeast France that was at least 66 years old. Its seeds, rather than being wind-borne, are carried in fruits (Kaufman & Kaufman, 2007). In addition, English Ivy appears to be capable of establishing or persisting in late-successional as well as disturbed communities (Waggy, 2010). English Ivy is therefore closer to being a K-strategist than an r-strategist. Its pattern of survivorship also supports this conclusion. English Ivy can spread via runners, bird-dispersed seeds, or cuttings in contact with earth (Kaufman & Kaufman, 2007).

The primary method of reproduction for Vinca minor and Aegopodium podagraria are underground runners from rootlets (Kaufman, Kaufman, 2007). Both of the species rarely repopulate from seeds. The seeds from Goutweed need very specific conditions to survive after germination, the requirements are recently disturbed soil and a sunny location (CVC, 2017) Both Periwinkle and Goutweed have attributes that make them r-strategist species. The r-strategists attributes the species have are rapid growth rate, and frequent reproduction through the runners and quick to maturity.

Lily of the valley, Convallaria majalis propagates by two methods. During warm months the plant sends out underground stems called rhizomes, which form new upright shoots called stolons. In the spring these grow into new leafy shoots that still remain connected to the other shoots under ground, and often form large colonies. It also produces a small, white, sweetly scented flower that produces a small orange-red berry. The berry contains a few large whitish to brownish colored seeds that dry to a clear translucent round bead. Majalis cannot self fertilize and it is self-sterile, if there are not two colonies available to cross pollinate the plant will not be able to seed. (Chace & Coover, 2012).

Survivorship 

The survivorship of many invasive species are type three, with high mortality at seedling stage of life followed by high rate of survival among the fully grown (Molles, Cahill, 2014) The type three curve fits the survivorship of Periwinkle, Goutweed and Lily of the Valley because of the low chance of seedling for the plants to germinate. However through the reproductive strategy of runners there is a higher chance of surviving due to the main body being established, Figure 3 shows a survivorship curve representing the three survivorship types based on organisms survived over time.

The germination rate of English Ivy seeds is near 100%, especially with the pulp removed via digestion by birds (Biggerstaff & Beck, 2007). Low juvenile mortality suggests either a Type I or II survivorship curve depending on whether mortality rates are greater (Type I) or the same (Type II) among older individuals (Molles & Cahill, 2014).

survivorship_curve
Figure 11: Three Types of Survivorship Curve (Husthwaite, 2009)

Dispersal and Vectors Vector_Human

The primary vector for Common Periwinkle, Goutweed and Lily of the Valley would be humans; Humans either improperly dispose of the garden waste produced by these plants or they plant these groundcovers due to the beautiful flowers produced, easy maintenance and edibility. (Kaufman & Kaufman. 2007) Because of the rhizomes on the roots, the plant can easily be establish in the compost. (CVC, 2017) Due to these plants being widely distributed and sold by plant nurseries and lack of education on the impacts they have ecologically, consumers may plant them on their property were the invasive plants can easily escape into the surrounding environment.(Darcy & Burkart. 2002). Common periwinkle is known to be dispersed throughout its native range by the means of ants (Stone, 2009), it is currently unknown whether or not this occurs in North America. Due to the toxicity of lily of the valley no known species disperse the seeds over a long distance. Goutweeds main dispersal agent is gravity and the wind pushing the seeds a small distance, it is currently unknown if animals aid in the dispersal of ribbed seeds that could adhere onto fur. (Waggy, 2010) Due to the lack of seeds that these plants produce, this prevents any major dispersal over varying distances, however if unchecked the plants can overtake a substantial area through the underground root systems. English Ivy and other invasive groundcovers are still planted in gardens, where they can grow into natural areas(Ontario’s Invading Species Awareness Program, n.d.). The seeds of English Ivy can also be dispersed by birds (Kaufman & Kaufman, 2007).

Special Considerations

The juvenile and adult stages of English Ivy differ greatly in growth form, reproductive capacity, and leaf shape (Castagneri, Garbarino, & Nola, 2013). These differences are summarized in Table 1. The leaves of the adult form have greater total photosynthetic capacity than the leaves of the juvenile form. However, the leaves of the juvenile form are better at adapting to changing light levels due to greater phenotypic plasticity (Bauer & Thöni, 1988). English Ivy has some medicinal uses and is capable of causing contact dermatitis (Kaufman & Kaufman, 2007; Paulsen, Christensen, & Andersen, 2010).

Table 1: Comparison of juvenile and adult Hedera helix. Adapted from Castagneri, Garbarino, & Nola, 2013.

Characteristic Juvenile Adult
Growth Form Prostrate                                             Climbing
Reproductive Capacity Sterile Fertile
Leaf Shape Palmately lobed Unlobed, oval-shaped

Convallaria majalis and Aegopodium podagraria are both non-native to North America and have no known predators in their introduced habitats.  Vinca minor , however has been noted in Illinois to have one known predator, which is White-tailed deer. One consideration of these species is if they are being removed through excavation the entire root mass and all runners should be removed to prevent the organisms from re-establishing. All species have been known in the past to be used for medicinal and ornamental purposes. Lily of the Valley is toxic to most animals.

References

Bauer, H., & Thöni, W. (1988). Photosynthetic light acclimation in fully developed leaves of the juvenile and adult life phases of Hedera helix. Physiologia Plantarum, 73(1), 31-37. doi:10.1111/1399-3054.ep12975682

Biggerstaff, M. S., & Beck, C. W. (2007). Effects of English Ivy (Hedera helix) on Seed Bank Formation and Germination. American Midland Naturalist, 157(2), 250-257.

Castagneri, D., Garbarino, M., & Nola, P. (2013). Host preference and growth patterns of ivy (Hedera helix L.) in a temperate alluvial forest. Plant Ecology, 214(1), 1-9. doi:10.1007/s11258-012-0130-5

Chace, T. D., & Coover, C. (2012). The anxious gardener’s book of answers. Portland, Or.: Timber Press.

Chace, T.D. (2013) How to Eradicate Invasive Plants. Portland Oregon: Timber Press Inc.

Credit Valley Conservation, (2017) Invasive Plants (Aquatic & Terrestrial), Your Land and

Water, retrieved on January 26, 2017, from http://www.creditvalleyca.ca/your-land-water/tree-planting-and-habitat-restoration-services/invasive-species/invasive-species-spotlights/invasive-plants-spotlight/

Darcy, A.J., & Burkart, M.C. (2002). Allelopathic Potential of Vinca minor, an Invasive Exotic Plant in

West Michigan Forests. Bios, 73(4), 127-132. Retrieved fromhttp://www.jstor.org/stable/460864

D’Hertefeldt, T., Enestrom, J., & Pettersson, L.B. (2014) Geographic and Habitat Origin Influence Biomass Production and Storage Translocation in Clonal Plant Aegopodium podagraria. Plos ONE, 9(1), 1-8

EDDMapS. (2017) Early Detection & Distribution Mapping System. The University of Georgia –

Center for Invasive Species and Ecosystem Health. Available online at http://www.eddmaps.org/; last accessed January 25, 2017.

Garske, S. Schimpf, D. (2005) Fact Sheet: Goutweed. Plant Conservation Alliance’s Alien Plant Working Group. Retrieved from http://www.nps.gov/Plants/aliean/Fact/aepol.htm

iNaturalist, (2017) Lesser Periwinkle (Vinca minor) map/about, iNaturalist.ca, retrieved on January 27, 2017, from http://inaturalist.ca/taxa/55844-Vinca-minor

Kaufman, S.R., & Kaufman, W. (2007). Invasive plants. Mechanicsburg, PA: Stackpole Books.

Londré, R.A., & Schnitzer, S.A. (2006). The distribution of lianas and their change in abundance in temperate forests over the past 45 years. Ecology, 87(12), 2973-2978. Retrieved from http://isites.harvard.edu/fs/docs/icb.topic941093.files/Week%205.%20Vine%20Distribution%20Temperate%20Forests%20%20Ecology.pdf

Molles, M.C., & Cahill, J.F. (2014). Ecology: concepts and applications. Canada: McGraw-Hill Ryerson.

OISAP, (2017) Invasive Ground Cover, Ontario’s Invading Species Awareness Program, retrieved on January 27, 2017, from http://www.invadingspecies.com/invaders/plants-terrestrial/invasive-ground-covers/

Ontario’s Invading Species Awareness Program. (n.d.). Grow me instead: beautiful non-invasive plants for your garden. Retrieved from http://www.invadingspecies.com/invaders/plants-terrestrial/invasive-ground-covers/

Pascoe, M. (2017).Hedera helix ‘Thorndale’ (Thorndale English Ivy). Retrieved from  http://www.canadaplants.ca/display.php?id=89

Paulsen, E., Christensen, L. P., & Andersen, K. E. (2010). Dermatitis from common ivy ( Hedera helix L. subsp. helix) in Europe: past, present, and future. Contact Dermatitis (01051873), 62(4), 201-209. doi:10.1111/j.1600-0536.2009.01677.x

Schnitzler, A., & Heuzé, P. (2006). Ivy (Hedera helix L.) dynamics in riverine forests: Effects of river regulation and forest disturbance. Forest Ecology And Management, 23612-17. doi:10.1016/j.foreco.2006.05.060

Stone, K.R (2009) Vinca Major, V, Minor. In: Fire Effects Information System [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Retrieved from http://www.fs.fed.us/database/feis/plants/vines/vinspp/all.html

Vandepitte, K., De Meyer, T., Jacquemyn, H., Roldan-Ruiz, I., & Honnay, O. (2013). The Impact of extensive clonal growth on fine-scale matting patterns: a full paternity analysis of a lily-of-the-valley population (Convallaria majalis). Annals of Botany, 111(4), 623-628

Verstraeten, G., Baeten, L., De Frenne, P., Thomaes, A., Demey, A., Muys, B., & Verheyen, K. (2014). Forest herbs show species-specific responses to variation in light regime on sites with contrasting soil acidity: An experiment mimicking forest conversion scenarios. Basic and Applied Ecology, 15316-325. doi:10.1016/j.baae.2014.05.002

Waggy, M.A. (2010). Hedera helix. Retrieved from https://www.fs.fed.us/database/feis/plants/vine/hedhel/all.htm

Image Credits:

chery. (2006, October 16). Hedera helix clinging. Retrieved from https://commons.wikimedia.org/wiki/File:Hedera_helix_clinging.jpg    

Husthwaite, R. (2009, April 23). Survivorship curves. Retrieved from https://commons.wikimedia.org/wiki/File:Survivorship_Curves.jpg

Kenraiz. (2008, November 15). Hedera helix native range. Retrieved from https://commons.wikimedia.org/wiki/File:Hedera_helix_area_kz1.png

United States Department of Agriculture. (n.d.). Hedera helix North American range. Retrieved from http://bioweb.uwlax.edu/bio203/s2009/hitchins_abby/Habitat.htm

Peters, K. (2005, July 15). Aegopodium podagraria blatt. Retrieved from https://commons.wikimedia.org/wiki/File:Aegopodium_podagraria_blatt.jpg

Zell, H. (2009a, April 14). Vinca minor 001. Retrieved from https://commons.wikimedia.org/wiki/File:Vinca_minor_001.JPG

Zell, H. (2009b, April 29). Convallaria majalis 0001. Retrieved from https://commons.wikimedia.org/wiki/File:Convallaria_majalis_0001.JPG