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Maryland White-tailed Deer Biology
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White-tailed Deer
Classification |
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Kingdom – Animalia |
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Phylum – Chordata |
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Class – Mammalia |
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Order – Artiodactyla |
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Family - Cervidae |
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Genus – Odocoileus |
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Species – virginianus |
Native white-tailed deer live in all 23 Maryland counties across a wide
range of landscapes. An exotic sika deer inhabits the wetland habitats of
Dorchester, Somerset, Wicomico and Worcester counties.
The white-tailed deer’s distinctive white tail and white rump patch is
readily visible when they bound away from real or perceived danger.
White-tailed deer sprint up to 35 miles per hour and are able to leap over 8
foot tall barriers.
Adult white-tailed deer are about three feet tall at the front shoulders.
Maryland yearling bucks (males) weigh an average of 135 pounds; yearling
does (females) average 120 pounds. During the warm months, deer possess
reddish-brown hair. A grayish-brown coat with a thick undercoat replaces the
reddish hair during the cold time period.
Maryland white-tailed deer habitats include most parts of the state except
for open water and the intensely developed urban areas (e.g. downtown
Baltimore). Deer thrive in landscapes with wooded/brush sections and open
areas such as cropland, pasture or landscaped yards. Deer use the wooded
areas for food and cover, and open areas provide food. Landscapes with a
bountiful interface of the forest and open areas support prime deer
habitats.
Suburban sprawl creates ideal habitat conditions for white-tailed deer. When
forested areas are converted into housing developments, portions are cleared
for roads and home sites, while other sections remain forested. When open
farmland is transformed into residential areas, new homeowners plant trees,
shrubs and perennials. Both of these types of residential conversions
provide excellent deer habitat.
Deer feed on nuts and berries, leaves, woody shoots and stems, grasses and
cultivated crops. Some of their favorite natural foods include acorns,
honeysuckle, poison ivy, green briar, young tree seedlings and mushrooms.
Soybeans, corn and ornamental shrubs are several of their favorite foods
planted by man.
Deer have a four-chambered stomach that is required to digest the
vegetation. Food first travels to the rumen that contains the bacteria and
protozoans, which begin the digestive process. The reticulum circulates food
back to the mouth so that the deer can chew the food again. The omasum
functions as a pump and directs the partially digested food from the
reticulum to the abomasum. This final chamber functions as a true stomach
and completes the digestive process.
Only white-tailed bucks possess antlers. On extremely rare occasions does
may exhibit antlers. Bucks use their hard antlers to establish dominance
over other bucks during breeding season. Antlers are grown and shed each
year. Antlers, which are composed of true bone, begin to grow in late March
and early April. The growing antlers are covered with skin and blood vessels
called velvet.
During late summer, testosterone hormonal levels elevate and the antlers
start to harden and the velvet is shed. By mid January when the testosterone
levels decline, antlers begin to drop. Bucks in the best physical condition
will lose their antlers last.
Maryland white-tailed deer breeding season begins in October and continues
until about mid December. The shortening of day length (photo period)
triggers the breeding season. Most does become pregnant during the first
half of November. One dominant buck can breed numerous does. Any receptive
doe that does not become pregnant will recycle back into estrous in about 28
days and mates again.
Fawns (baby deer) are born during May and June after a gestation period of
about 200 days. Yearling does usually give birth to single fawns. Mature
does in good physical condition frequently produce twins.
Newborn spotted fawns remain hidden and solitary for about three weeks. The
doe visits her young only two to three times per day in order to nurse and
groom the offspring. When the fawn is strong enough to run with the doe, it
will follow its mother and begin to sample foods eaten by the doe. Fawns can
live independently of their mother at about two months old.
Hunting causes the primary mortality of white-tailed deer in most of
Maryland. Other deer mortality factors include vehicle collisions, diseases,
malnutrition and accidental injuries. Vehicle collisions, diseases and
malnutrition become primary mortality factors in sections of Maryland with
limited hunting (suburban and urban locales).
In pre Colonial Maryland, wolves, mountain lions and man (Native Americans)
functioned as effective predators of white-tailed deer. All were capable of
taking any age class of healthy deer (fawns, adults). Bears and coyotes (a
recent immigrant to Maryland) are only capable of catching very young fawns
or sick/injured adults. Only man remains as a modern time effective
predator- either with a motor vehicle or hunting device.
When deer habitat is destroyed (e.g. construction of shopping mall complex),
deer numbers are indirectly reduced. As large sections of land are converted
to intense developments such as shopping centers or industrial areas, deer
numbers decline in these locales.
The typical annual average home range for white-tailed deer is considered
about one square mile (640 acres). However, the sex and age of the deer and
habitat types will influence varying size home ranges. Yearling males will
move many miles while adult females usually have smaller stable annual home
ranges. Deer in quality habitat will need to travel less than deer in poorer
quality habitat.
The white-tailed deer’s future in Maryland remains bright. Only the most
intensely developed and industrialized sections of Maryland fail to provide
white-tailed deer with suitable habitat. Since white-tailed deer feed on a
wide variety of plants (native, exotic, ornamental and cultivated) food will
not be a limiting factor of deer.
Douglas Hotton
Deer Project Leader
Maryland DNR, Wildlife & Heritage Service
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