White-Tailed Deer

 

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There are 38 subspecies of white-tailed deer in the Americas, of which 16 are in North America

ommon Name: White-Tailed Deer, Common deer, Jumping deer, Virginia deer – The white underside of the tail that is used as a warning flag when the animal is alarmed.

Scientific Name: Odocoileus virginianus  – The Genus is from the  Greek odous, hollow and koilos, tooth, for the characteristic depressions in the surface of the molar teeth; species virginianus for its having been first sighted and categorized in Virginia.

Potpourri: The white-tailed deer is a member of the Cervidae Family (the Latin word for deer is cervus) which includes moose, elk and caribou. The characteristic feature of the family is that the males (and females in the case of caribou) have antlers instead of horns. The distinction is that horns are hollow and permanent, whereas antlers are solid bone that fall off and regenerate every year. There are 43 species of deer worldwide that first appeared in the late Oligocene, about 30 million years ago, originally in Asia. Depending on the species, males are called stags, harts, bucks or bulls, females are called hinds, does or cows, and the young are called calves or fawns.

There are 38 subspecies of white-tailed deer in the Americas, 16 in North America, ranging from the endangered Key Deer (O. virginianus spp clavium) of Florida to the Coues Deer (O. virginianus spp cousin) of the Southwest. The subspecies (ssp virginianus) indigenous to the Southern Appalachians consists of bucks and does that live about 10 years, producing between one and four fawns every year.

It is estimated that there were between 20 and 40 million white-tailed deer in North America before the arrival of Europeans. The population declined over several centuries due to habitat loss and hunting, but recovered starting about the middle of the last century to the point that there are now an estimated 14 to 20 million in the United States alone. This is attributed to a variety of causes: the decrease of natural predators such as wolves and cougars; an expansion of food supplies; the restoration of arboreal habitat as once farmed fields are left fallow; and the behavioral flexibility of the deer.

The social structure of the deer population contributes to their ability to adjust to new environments. The basic social unit is the doe and her fawns. Does are polyoestrous, meaning they come into heat twice, the first time for 24 hours and the second 28 days later. Mating between October and December, they fawn in early summer. During the first few postpartum weeks, the doe keeps the fawns hidden from predators (such as coyotes, responsible for as much as 40% of fawn mortality) by leaving them in dense undergrowth while foraging, twin fawns being separated. The fawns remain immobile, even withholding their feces and urine until the return of the doe; she ingests their waste so as to leave no trace scent. White-tailed deer are prolific. Annually, about 140 fawns are born for every 100 does, though about a third of the fawns do not survive.

Bucks grow antlers to fight for mating rights and not to ward off predators, a stark example of survival of the fittest and strongest. The antlers grow as dermal covered projections from a bony base called a pedicel. The velvety covering contains blood vessels and nerves to sustain the growth. When the antlers reach full size just before mating season, the “velvet” dies and the buck removes it by rubbing his head against trees, producing tell-tale rub marks on the bark. These “buck rubs” have glandular secretions that serve as markers for the buck’s territory. Bucks generally live alone or with other bucks in small groups.

As mating season approaches, sparring between bucks for dominance of the group begins. This consists of two bucks locking horns to attempt to push each other backwards. As a doe goes into heat, sending pheromones from glands on the legs, the dominant buck follows, fighting off any intruders to complete the mating process. A single dominant buck may mate with up to 20 does. Bucks attract females by creating a scrape, a one to three foot diameter area that has been cleaned of underbrush to expose the bare earth to which generous amounts of his urine have been applied. Does visit the buck rubs and scrapes during the rutting season and urinate on them, providing a trail for the buck to follow.

White-tailed deer feed on a wide variety of vegetation, ranging from twigs, leaves and bark in the forest to ornamental shrubs and agricultural crops near human habitation, consuming about 7 pounds a day. Among their favorite natural foods are acorns, poison ivy, green briar, honeysuckle, and young tree seedlings. They have a four chambered stomach that allows them to digest almost anything. Food travels to the rumen which contains bacteria to break down the vegetation. The reticulum circulates the food back to the mouth as cud to be chewed again, whence the omasum pumps the food to the abomasum to complete the process.