White-Tailed Deer

Odocoileus virginianus

Hunting season began several weeks ago and one of the primary animals being hunted is an animal we might just as easily spot in our backyards as in the woods—the white-tailed deer.  The white-tailed deer is beginning its rut soon (most sources estimate that the white-tailed deer population of Western Montana breeds from late November to early December).  During this period, bucks mark their territory with ‘scrapes’ and ‘buck rubs’ and compete with other bucks for territory and mating privileges.

Distribution

White-tailed deer are the most widely-distributed and most common of the large mammals in North America, with populations occurring in Southern Canada and stretching into Mexico.  There are only a handful of areas in the United States in which white-tailed deer are absent—Hawaii, Alaska, and parts of the Southwest.  White-tailed deer populations nationwide have exploded.  In the early 1900s, there were roughly 500,000 white-tailed deer in the nation.  Current figures put the population at somewhere between 15 and 20 million.  The white-tailed deer population’s successful rebound has been contributed to the implementation of hunting regulations and the founding of federal agencies charged with managing and maintaining natural resources.  Furthermore, the elimination and drastic reduction of populations of key deer predators, such as grey wolves and mountain lions, has contributed to this rebound.  The white-tailed deer’s move from relative scarcity to such large numbers is now becoming problematic for people who find themselves struggling to keep deer out of their backyards or worry about possible deer collisions when driving.  According to Montana FWS estimates, the state of Montana’s population of white-tailed deer is 249,001. 

White-Tail

The distinguishing feature of the white-tailed deer (from which its name derives) is the white underside of its tail, which it sometimes displays while running.  Several hypotheses have been given for the evolutionary advantage of the white-tailed deer’s ‘flagging’ behavior—including that it communicates awareness to a would be predator, that is alerts fellow deer to potential danger, or that it can be a cohesive signal, particularly for a doe to keep her fawns nearby.  So far, there hasn’t been enough conclusive evidence to determine which of these hypotheses might explain the deer’s ‘flagging’ behavior. 

Antlers

The male white-tailed deer have antlers which they shed and re-grow every year.  Antler growth begins in March or April and deer antler growth can reach astonishing rates.  Some bucks’ antlers will grow as much as ½ an inch in a single day!  The antlers continue to grow throughout the summer months and are covered in a soft skin called ‘velvet.’  In the fall, the antlers harden during the process of calcification.  During the fall, you might also spot bucks rubbing their antlers against tree trunks in an attempt to remove the velvet from their antlers.  Bucks also use their antlers to mark their territory with ‘buck rubs’ and as a weapon in clashes with other bucks when defending or fighting for territory.  The bucks lose their antlers in the dead of winter.  These antlers, rich in calcium build-ups and other nutrients, are understandably difficult to find in the woods.  Upon falling to the forest floor, they are quickly devoured by squirrels, mice, porcupines, and other small animals. 

Deer-Car Collisions        

1.5 million deer-automobile collisions cause an estimated $1 billion in automotive damages and 200 deaths annually.  According to State Farms, Montana has the 4^th highest frequency of deer-car collisions, and 1 in 82 drivers in Montana will have collisions with a deer over the course of the next year.  The construction of wildlife crossings, such as those recently added to Highway 93 (read more in this article from the Missoulian) might reduce the frequency of deer and human fatalities resulting from automobile collisions.  Deer-car collisions generally peak during breeding season as males, in their frenzied competition, temporarily lose their cautiousness.  And, as winter sets in, deer come into our backyards in search of food, and are most active at dusk and at dawn.  Drive cautiously!