Deer

Basic Information

Anatomy

Males regrow their antlers every year.

Genetics and Reproduction

Females enter estrus, colloquially called the rut, in the autumn, normally in late October or early November, triggered mainly by the declining photoperiod. Sexual maturation of females depends on population density, as well as availability of food. Young females often flee from an area heavily populated with males. Some does may be as young as six months when they reach sexual maturity, but the average age of maturity is 18 months. Copulation consists of a brief copulatory jump. Females give birth to one to three spotted young, known as fawns, in mid- to late spring, generally in May or June. Fawns lose their spots during the first summer and weigh from 44 to 77 lb (20 to 35 kg) by the first winter. Male fawns tend to be slightly larger and heavier than females. For the first four weeks, fawns are hidden in vegetation by their mothers, who nurse them four to five times a day. This strategy keeps scent levels low to avoid predators. After about a month, the fawns are then able to follow their mothers on foraging trips. They are usually weaned after 8–10 weeks, but cases have been seen where mothers have continued to allow nursing long after the fawns have lost their spots (for several months, or until the end of fall) as seen by rehabilitators and other studies. Males leave their mothers after a year and females leave after two.

Bucks are generally sexually mature at 1.5 years old and begin to breed even in populations stacked with older bucks.

Dietary Needs and Habits

deer eat large amounts of food, commonly eating legumes and foraging on other plants, including shoots, leaves, cacti (in deserts), prairie forbs, and grasses. They also eat acorns, fruit, and corn. Their special stomachs allow them to eat some things humans cannot, such as mushrooms and poison ivy. Their diets vary by season according to availability of food sources. They also eat hay, grass, white clover, and other foods they can find in a farm yard. Though almost entirely herbivorous, white-tailed deer have been known to opportunistically feed on nesting songbirds, field mice, and birds trapped in mist nets, if the need arises. A grown deer can eat around 2,000 lb (910 kg) of vegetable matter annually. A foraging area around 20 deer per square mile can start to destroy the forest environment.
The deer is a ruminant, which means it has a four-chambered stomach. Each chamber has a different and specific function that allows the deer to eat a variety of different foods, digesting it at a later time in a safe area of cover. The stomach hosts a complex set of microbes that change as the deer's diet changes through the seasons. If the microbes necessary for digestion of a particular food (e.g., hay) are absent, it will not be digested.

Additional Information

Perception and Sensory Capabilities

It raises its tail when it is alarmed to warn the predator that it has been detected.

Scientific Name

Odocoileus virginianus

Average Weight

Males usually weigh 68 to 136 kg (150 to 300 lb) Females usually weighs from 40 to 90 kg (88 to 198 lb).

Body Tint, Colouring and Marking

The deer's coat is a reddish-brown in the spring and summer and turns to a grey-brown throughout the fall and winter. The deer can be recognized by the characteristic white underside to its tail.