Ecological Profile: White-tailed Deer, Odocoileus virginianus
The white-tailed deer, Odocoileus virginianus, has a broad range covering the majority of Canada’s lower regions from British Columbia to Prince-Edward-Island, excluding parts of Newfoundland. The deer have expanded their range into the more northern boreal ecosystem of Canada, which can be identified by the increase in abundance of wolf populations (Dawe, K., Bayne, E., & Boutin, S., 2014). The white-tailed deer are also found throughout America excluding Hawaii, Alaska, lower southwest regions and northern parts of South America (Figure 1. Indicates Ontario distribution of the White-tailed Deer).
Figure 1: Orange areas display the dispersal of White-tailed Deer in Ontario, Canada. Map created using ArcGIS.
Figure 2: Global distribution of White-tailed deer
White-tailed deer prefer areas with dense pockets of shrubs to hide in (i.e. bedding). They also prefer wide open areas to graze in such as agricultural fields. Having a field full of crops near a stream with a great deal of wooded area is the perfect conditions for deer. White-tail deer live in many habitats like forested areas of hardwoods or conifers, they also exist in swamp sand can be seen using creeks as a source of water or transportation. White-tailed deer are adapted to various sites throughout the western globe ranging from boreal forests, grassy plains, Carolinian forests, and some arid regions of America. Over winter the White-tailed deer prefer areas of Eastern Hemlock (Tsuga canadensis) (Donovan, June 4, 2013) which provide shelter from harsh winter conditions. These areas are preferred due to their ability to provide food for the deer year round in the form of small shrubs and trees while providing shelter from prey for both adults and young. During the early morning and late evening the white-tailed deer will spend its time grazing along forested edges on shrubs, low hanging branches and when available, agricultural land (Donovan, 2013). Deer is the most popular and plentiful game animal in America making humans the biggest predator for the deer. So as the increase in human activity happens within an area the more need for them to have cover. (Hummel, S. ‘., Campa, H. I., Locher, A., & Winterstein, S. R., 2016).
The male white-tailed deer begins his rut during the fall season where both Male (Buck) and Female (Doe) search for mates (Georgia, September 28, 2015). The Buck will begin to mark out boundaries using urine and tree scratching as markers. Bucks compete for dominance through fighting using their antlers which by winning increases their odds of breeding with Does. The Does after giving birth will rear the fawns for two months before bringing them into a herd where they can then be protected by the group. Having a long lifespan with a small litter size are common characteristics of ‘K’ strategy species, alongside parental care to help the young survive. The information to support this species as a ‘K’ strategy in summarized in table 1 (Georgia, 2015).
Table 1: Identifies the White-tailed Deer, Odocoileus virginianusas, a K-Strategist following certain characteristic requirements.
|Litter Size||Large||Small||1 to 3 Fawns|
|Parental Investment/Care||Very little if any||Required||Required|
|Frequency of Reproduction||Once to multiple times over short time period||Multiple ties but over a prolonged period||Once a Year|
|Additional Factors||Most reproductively mature individuals reproduce
|Few reproductively mature
individuals or only some reproduce successfully
|-Good survival rates
White-tailed deer have a fairly even probability of surviving in the wild, which demonstrates this species as a Type II on the survivorship curve graph (see Figure 3). There is a relationship between the habitat and survivorship in the deer population. Studies have demonstrated that in the wintertime, deer with higher survivorship would choose areas with more cover value than deer with poorer survivorship. In the summertime, it is predicted that deer with higher survivorship would choose ranges with preferred forage over deer with lower survivorship. (Klaver et al, 2008)
Figure 3: White-tailed deer have a Type II survivorship curve due to the relative evenness of survival throughout the species life time. (Feltham, 2017)
Dispersal and Vectors
Deer usually stay in the new area during dispersal and don’t return to their original home range. Male white-tailed deer that are less than three years old make up most of the dispersal movement in the deer population. They are the ones who separate from their mothers when they are young and begin their ‘trips’ while the females are only a small percentage when it comes to dispersal because they stay with their mothers for about a year once they are born. White-tailed deer go through dispersal because they are competing for mates and to also avoid inbreeding within their population. Forage conditions are a big factor when the deer start to disperse. It is a barrier because they travel through the land on foot. Some of the core areas of the home range may temporarily be in decline because of drought so they travel to find sites with better forage or cover that they can temporarily use. Another factor includes the drying of water sources. This force’s the herds to travel to areas that are less disturbed and better watered. (Hewitt, David G. 2011)
The white-tailed deer is the primary host for the black legged tick (xodes scapularis), a vector for Lyme disease. Researchers have thought about whether decreasing the quantity of deer in a specific region would mean less instances of the disease. There was a 13-year study done in Connecticut and they have found that there were diminished deer populations that lead to a decrease in the disease. This lessened the population of the deer, therefore reducing the potential for the ticks to breed effectively. Breeding is an important factor for any long-term strategy to reduce the risk of humans contracting Lyme disease. (Entomological Society of America, 2014)
In the Northern part of their range, the white-tailed deer will regularly migrate as a result of the winter climate. This is because of their physiological and nutritional requirements. From forest landscapes to agriculture they demonstrate a variety in the dates of relocation and their strategy for movement. (Fieberg, Kuehn, Delgiudice, 2008) White-tailed deer are facultative migrators (conditional). They are classified under this if they do not migrate during the documented migration dates or if they make a few excursions to a regular home range for under 1 month. (Grovenburg et al., 2009)
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.
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 movements 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