A white-tailed deer's diet varies depending on the season, but the deer typically eat grass, legumes, twigs, leaves and alfalfa. A white-tailed deer living in a desert environment also eats cacti. Its four-chambered stomach allows it to eat foods that humans cannot eat, including mushrooms, lichen and poison ivy. It is typically an herbivore, but consumes nesting songbirds and mice if given the opportunity.
The four-chambered stomach allows the deer to digest its food later after it is safely under cover. Each stomach chamber has a specific function. The rumen and the reticulum are the first two chambers, and these mix the food with bile to form a cud. The deer regurgitates the food and chews it again before the food passes to the omasum, which removes water. The abomasum sends the food into the small intestine, and the small intestine absorbs the food's nutrients.
White-tailed deer range from Canada to South America, and people have introduced the deer into Jamaica, New Zealand, Cuba, the Bahamas and Finland, among other locations. They prefer fields with deciduous trees for cover in the summer and conifer forests in the winter. Adults have reddish brown coats in the summer that fade to greyish-brown in the winter, and bucks grow a set of antlers each year.