The graceful white-tailed deer Odocoileus virginianus is well known to most North Americans. Hunters and nonhunters alike recognize the animal by its habit of flourishing its tail over its back, revealing a stark white underside and white buttocks. This "flag" of the white-tailed deer is often glimpsed as the high spirited animal dashes away from people. The tail has a broad base and is almost a foot long. When lowered, it is brown with a white fringe.
In summer, the white-tailed deer has a reddish pelage, or fur, on its back and sides and is whitish beneath. In winter the upper parts turn greyish. Full grown male deer frequently exceed 1 m at shoulder height and 110 kg in weight, with exceptional individuals weighing up to 200 kg in the northern part of their range.
The antlers of the mature male white-tail consist of a forward curving main beam from which single points project upward and often slightly inward. Perhaps one of every 1 000 females also bears small, simple antlers.
Abundant food makes almost any forested or bushy area suitable for white-tailed deer during the summer, but as snow deepens the deer concentrate in "deer yards," or areas that provide food and shelter from storms and deep snow. Sometimes the move from summer to winter range requires travelling many kilometres.
The doe leaves her fawn unattended for hours at a time. When the fawn remains bedded, the natural camouflage of its spotted coat and its almost scentless condition effectively conceal it from predators. The doe returns at intervals to suckle the fawn.
People sometimes chance to find fawns in their secluded hiding places and mistakenly believe they have been deserted by their mothers. In fact, a doe will rarely desert her fawn, and the little animals should not be touched. Human scent on the fawn may cause the doe to desert it.
During the spring and summer the white-tailed deer’s diet consists of leafy material from a variety of woody plants, grasses, herbs, and forbs. It also includes such delicacies as fiddleheads, mushrooms, and blueberries. When summer’s lush vegetation turns brown and dry in autumn, the deer must depend largely on the twigs and buds that are within their reach. Acorns are a favourite autumn food for white-tailed deer living in eastern Canada, and in Western Canada grain piles left in fields attract white-tailed deer throughout the autumn and winter. Even in winter white-tailed deer consume green forage, such as winter-green forbs, grasses, and sedges.
Even the most favourable winter concentration areas have a limited food supply. If there are too many deer using the area, the most nutritious fodder disappears rapidly, leaving foods of only marginal value for the remainder of the winter. Deep snow worsens the problem. When snow is deeper than 40 cm, deer find it increasingly difficult to move about freely and tend to follow previously broken trails. The quantity and quality of food that can be reached from these trails further limit nutritional intake at the very time that intense cold and difficult travel tend to increase the deer’s energy requirements.
Converting surplus fat stored during the late summer and early autumn meets some of this energy requirement, but once this remaining source of energy has been depleted, there is less likelihood of the deer surviving until spring. If food remains scarce and the deer begin to break down muscle tissue for energy, then the chances of survival become extremely poor. It is not surprising that those that do survive a severe winter return to their summer ranges as little more than gaunt shadows of their sleek autumn form. The green growth of spring brings welcome relief.
Deer reproduce quickly. A healthy herd is capable of almost doubling its numbers during one favourable year. Under favourable conditions, female fawns tend to breed at six to seven months and at 12 months of age produce singletons, or one baby. Male fawns and male yearlings are sexually mature but are seldom given a chance to breed.
The white-tailed deer’s spotted, wobbly legged fawns, weighing 2 to 4 kg at birth, are born in late spring. Although birth may take place from late March to early August, most fawns are born during the last week of May or the first week of June. On high quality range twin fawns are the rule, although single births are quite common among younger females, especially those giving birth for the first time. Triplets are relatively uncommon and quadruplets occur only rarely. On poorer ranges or after a severe winter single births usually outnumber double births and multiple births do not occur.
The newborn fawn can get to its feet within minutes, and very soon takes its first nourishment from the doe’s rich milk; however, it remains relatively feeble during the first week or so of its life.
As the fawn grows stronger it begins to follow the mother about during her feeding and soon learns to supplement its milk diet by nibbling on succulent vegetation. The doe, meantime, like other adult members of the deer herd, has been feeding steadily on new spring vegetation. She has entered the spring period in lean condition and with a shabby, tattered winter coat. Gradually the coarse grey winter coat is replaced by the fine reddish summer coat. Improved food supply results in both doe and fawn becoming sleek and sturdy by midsummer.
In the early spring the antlers of the male begin to show as twin dark protrusions from the frontal bones of the head. Growth of the antlers and regaining of body weight continue rapidly through the late spring and early summer. Antlers are true bones and during growth have both an internal supply of blood through the pedicels, or branches, and an external supply in the hairy skin covering of the velvet. In late summer during advanced growth the antlers appear bulbous and distended under the velvet. The shortening days of late summer terminate growth of the antlers.
The velvet dries and begins to peel off, revealing the hard bony tissue beneath. Bucks rub their antlers against brush and small trees to speed this process. The antlers are usually shed in January although shedding may occur from December through March.
White-tailed deer are truly magnificent specimens in the early autumn. Their bodies are rounded out by reserves of fat stored for the lean months ahead. The new thick winter coat exaggerates the thickness and sturdiness of the body. Fawns have lost their spots and are now short-faced, smaller replicas of their parents. Most of the breeding occurs during the last three weeks of November although some fawns and yearlings breed in December and, rarely, into January. The peak of the rut, or period of male sexual activity, occurs during the last two weeks in November in Canada but is more variable in the southern U.S. Bucks with swollen necks, caused by hormones associated with the rut, travel almost incessantly, searching out the does and engaging in mock battles with their rivals. Sometimes a real battle develops, and occasionally the antlers of the combatants become hopelessly entangled, leaving both to die slowly.
Source : Hinterland Who's Who
Hinterland Who's Who
Wikipedia
New Hampshire Public Television
Chevreuil.net (french)
Le Gite du Rêveur (french)
CyberZoo (french)
Université Laval (french)
Centre d'expertise en analyse environnementale du Québec
Musée canadien de la Nature
