Mule Deer - Seasonal Behaviors

Seasonal Behaviors

In addition to movements related to available shelter and food, the breeding cycle is important in understanding deer behavior. The "rut" or mating season usually begins in the fall as does go into estrus for a period of a few days and males become more aggressive, competing for mates. Does may mate with more than one buck and go back into estrus within a month if they do not settle. The gestation period is about 190–200 days, with fawns born in the spring, staying with their mothers during the summer and being weaned in the fall after about 60–75 days. Mule deer females usually give birth to two fawns, although if it is their first time having a fawn, they often only have one. A buck's antlers fall off during the winter, to grow again in preparation for the next season's rut. The annual cycle of antler growth is regulated by changes in the length of the day. For more information see the main article on deer.

There are several non-human predators of mule deer. Gray wolves and mountain lions are the main predator of adult deer. These two leading natural predators often herd out weak, sickly or young specimens to kill but will also take down the largest and healthiest mule deer with some regularity as well. Bobcats, coyotes, wolverines, American black bears and brown bears are capable of preying on adult deer but usually either only attack fawns or infirm specimens or eat the deer after it has died naturally.