The first part of the common name refers to the 6-11 inches, bushy tail which the animal erects when disturbed, displaying the white hairs of the outer edge and under surface. Long, slender legs - each bearing two narrow, pointed hooves that support the weight - prominent ears, and in males, bony antlers (developed annually from pedicals of frontal bones in April-May and usually shed by February) are other characteristics. Molting produces marked seasonal changes in coat color which in summer is reddish brown, the hairs short, sparse, and wiry. The winter pelt is grayish brown, the hairs long, dense, and, because each hair contains insulating air spaces, brittle. In all seasons, the lower parts of the body, inner areas of the legs and ears, eye rings, a narrow band across the muzzle, and part of the throat are white. The nose, a small area on the chin, and the upper surface of the tail are black. Adults are about 71 inches in total length, and 39 in in shoulder height. The average weight of an adult male is 203 lb (maximum, 405 lb). The average weight of a female is about 155 lb (maximum, 218 lb).
Range and Habitat
The range is from southern Canada to Panama except for parts of the western and southwestern U.S. The white-tailed deer was uncommon in the Adirondacks prior to the mid 19th century. Today, this species resides in all terrestrial communities throughout the Adirondack Park, and is generally more numerous in the lowlands of the Park's periphery than in the central Adirondacks, especially the higher elevations (spruce-fir forests, above 2500 ft). The historical change in relative abundance and the current density reflect the availability of preferred habitat: The openings and edges of deciduous and mixed forests, the early successional stages of these forests, brushy fields, and wooded farmlands, together with mature stands of conifers that provide winter shelter. Disturbance (logging, the fires that followed, and finally, the hurricane of 1950) transformed the pristine Adirondack forests, which were less suited for deer, into more favorable habitat.
The primary change increasing the Adirondack deer herd was the conversion of large tracts of mature forest with its poorly developed understory into area of more diverse, low-growing, young vegetation which increased the food supply. Timber harvest on private lands continues to foster the Adirondack deer herd; the maturation of the public forest discourages it.
The white-tailed deer is, economically the most important wild mammal in the Adirondack Park, because of the approximately 150,000 hunters who participate in the annual season (average yearly harvest, 10,286). Nor should the importance of the species be overlooked in contributing to the wilderness experience of visiting campers, nature photographers, and hikers. For many visitors, the view of a white-tailed in the Adirondacks is the highlight of the their experience in the Park, overshadowing previous exposure to the same animal in the more mundane contexts of rural pastures and corn fields. Residents, too, are appreciative of the presence of white-tailed deer as part of their ordinary routines.
Food and Feeding Behavior
The white-tailed deer, an adaptable but selective herbivore, grazes and browses the most nutritious plants available. Feeding specialization include a four-part stomach containing bacteria and protozoans that aid in digesting cellulose, and a tough cartilaginous pad in place of the upper incisors. The six lower incisors and two canines work against the pad to crush and strip woody stems and twigs from their moorings. This feeding behavior causes ragged or frayed edges on the remaining portions of deer-browsed woody plants. Repeated browsing may create witches'-broom effect on saplings and shrubs.
White-tailed deer may stand on their hind limbs to reach desirable plants. This manner of feeding creates a noticeable browse line in white cedar swamps and where white cedar fringes lakes and rivers; almost all foliage and twigs are removed to a height of 6 ft. The effects of deer browsing are not limited to influencing the physical appearance of woody plants. At moderate to high densities, selective feeding by white-tailed deer may alter the species composition of regenerating forests by eliminating some trees and shrubs such a yellow birch, sugar maple, mountain ash and scarlet alder. Thus, this herbivore's impact on the Adirondack forests may be long-lasting.
Terrestrial and aquatic herbaceous plants, fungi, and fruits form much of the summer diet. Acorns and beechnuts (until buried by snow) and woody browse are important autumn and early winter foods, as well as dried leaves and grasses. After snowfall, the winter diet consists of woody browse - the twigs and stems of seedlings, saplings and shrubs. White tailed deer prefer white cedar, birches, aspens, American yew, hemlock, maples, ash, white pine, mountain ash, scarlet elder, sumac, witchhobble, and high bush cranberry. Beech, balsam fir, spruces, and larch are either unpalatable, indigestible, or both. The spring diet includes the buds, twigs, and developing foliage of woody and herbaceous plants.
An adult white-tailed deer requires approximately 5-7 lb of food per day. Energy demands vary seasonally, and are greatest for pregnant and lactating females, for males in the autumn rut, and for all individuals during severe winter weather.
However, metabolism, under control for photo period, declines in winter but increases from late winter to summer. Both browsing and fat reserves provide winter energy needs. Starvation, although probably always causing some mortality even during moderate Adirondack winters, may cause massive mortality when deep snow cover exceeds 100 days (as was the case in the winters of 1969-71).
Activity and Movement
White-tailed deer are primarily crepuscular (active at twilight) in the spring, but are active during the hours of daylight as well in the summer, including midday. By late autumn at the onset of the rut and throughout this period, bouts of activity occur equally at all times during a 24-hour period. Winter activity, mainly foraging, is more likely in late afternoon. Storms at any time of year may reduce activity, with slightly more movement taking place before and after inclement weather. General levels of activity increase with day length in late winter and spring, decline in summer and then peak again in late autumn. Deer stand quietly or bed down in cover when inactive.
Long periods of snow cover overlap the onset of increasing day length and metabolism. The depletion of fat reserves and the lack of nutritious browse (a persistent threat because of the repeated use of the same winter ranges) cause starvation; however, deer may lose 25-30% of their body weight and survive. Fawns from the pervious year are the most vulnerable to starvation because they have the least time to accumulate fat before winter. Severe winters affect not only the survival of white-tailed deer but also the productivity of females. Low energy levels may decrease the next crop of fawns.
White-tailed deer vacated their summer ranges when the snow depth reaches 15 inches, usually in late November or December, and travel up to 12 miles to reach traditional winter ranges (deer yards) that offer continuous coniferous cover overhead. Movement to the winter range is rapid, often less than 24 hours. Benefits of this habitat are not well-known, but may include reduced wind chill, easier movement (the snow sifts through the foliage and has a different physical character, or is shallower because the foliage retains part of the accumulation). Travel within the winter range is along well-defined trails, which is a key advantage for deer living in groups in winter; an individual saves energy by not having to continually create a new trail. The detection and escape from predators may be another advantage.
The return to the summer range begins when the snow depth recedes below 15 inches, and is a journey that takes place over the course of 1-2 weeks, often along slopes that face the south. Typically, the return begins in March or April, but it may begin with a sudden thaw in midwinter. If additional heavy snow falls, deer quickly move back onto the winter range. Walking, trotting, bounding, and running are the normal gaits of a white-tailed deer, which is capable of running at speeds up to 35 mph for several miles and leaping obstacles 8.5 ft in height. This species swims well, and frequently enters water in summer to forage.
The breeding season, or rut, is from late autumn to early winter (peak November 10). The gestation period is approximately 202 days. Females bred as yearlings bear one fawn. Older females usually bear twins throughout their lifetime, which in the Adirondacks, may span 10-15 years. Most fawns are born in late May or early June. At birth fawns weigh approximately 3-6 lb. Newborn fawns have a full coat of reddish brown fur that is spotted with white. Their eyes are open, and although somewhat unsteady on their legs, fawns nurse from a standing position when less than 24 hours of age. Fawns have little scent or odor for their first 7-10 days, and during this time, they tend to move little, except to nurse, and react to disturbance such as approaching predators by remaining motionless while flattened against the ground. Fawns begin to accompany the female when 3-4 weeks old, at which time they are already beginning to consumer some vegetation. Weaning is variable, usually by 4 months of age, but occasionally not until 6 months or longer. The winter grayish brown coat replaces the spotted pattern in September-Octover. Sexual maturity is at 1.5 years for both sexes, although many males will not actually breed until older. Potential longevity is 23-24 years; white-tailed deer 9-10 years old in the central Adirondacks are relatively common.
Chemicals from pedal (between the toes), preorbital (corners of the eyes), tarsal (inside of hind legs at the ankles) and metatarsal (outside of the hind legs between ankles and hooves) glands provide clues about the sex, age, identity and motivation of a deer. Deer deposit glandular substances in various ways, for example, when the hooves touch the ground, by pressing the preorbital glands on twigs and branches, and by urinating on the hind legs while rubbing the legs together (the stream of urine passing through the long hairs of the tarsal glands and carrying their products to the ground). An extensive repertoire of visual displays includes motor patterns and postures such as lowering the head with ears in different positions, standing on the hind limbs while lashing out or pawing with the front ones, and presenting a lateral view of the body, all of which are given in hostile encounters. Males in rut rub their antlers on small sapling or trees (deer rubs), use their hooves to expose soil in an area about 3 ft in diameter (scrapes) in which they rub-urinate to mark territories and then challenge intruding males. Contestants may shove or push with their antlers, the weaker male leaving. The upraised tail or flag is an alarm signal and may be preceded by the footstomp. Adults snort-wheeze, bawl, and moan in different contexts. Fawns give loud bleats or baas to summon their mothers, and whine while nursing.
White-tailed deer exhibit an elaborate social pattern. During the warm months of the year, the basic social unit consists of related females, their fawns and yearlings, and adult males all of which have contiguous or overlapping home ranges. In autumn, yearling males disperse up to 25 miles (average 5 miles) to establish permanent ranges with a different social unit.
The average size of the summer home range is 536 acres for both sexes, but during the rut, expands to 853 acres for males. White-tailed deer are polygamous. Each adult male competes with other males for access to females, and each male may exclude neighboring males from parts of its home range in the breeding season. All members of a social unit congregate at the same traditional winter range or yard where the home range size averages 338 acres per individual. Fawns accompany their mother to the winter ranges. Frequently, members of several social units use the same wintering area. Tradition largely determines the use of a particular yard. Thus, social units return to the same yard from one year to the next, sometimes passing by coniferous cover that appears to offer similar winter habitat. Social hierarchies are evident when deer congregate in herds, with rank determined by sex, age, and size. The largest males are dominant, followed in rank by adult females. Yearlings and fawns are subordinate to all others. Hierarchies determine access to food, especially when browse is limited. Densities of white-tailed deer for winter yards may approach or exceed 100-125 individuals per square mile, but are 4-25 deer per square mile for summer.
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