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.
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).
The 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).
Issues 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.
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.
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.
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.
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