Whitetail Deer (Odocoileus Virginianus)
Whitetail Deer are found throughout most of Southern Canada, the U.S., and Mexico. At one time the whitetail deer population of North America was estimated to be about 40 million. But settlement of North America by Europeans greatly reduced the population, reaching it's lowest levels between 1875 and 1915. One of the most amazing stories of wildlife conservation biology is that of the whitetail deer population in Missouri. Although abundant at the beginning of the 19th century when the Missouri deer herd was estimated to be between 400,000 and 600,000, by 1925 it was believed that only about 400 deer existed in the entire state. Hunting was forbidden for much of the time between 1925 and 1943. During this time deer were trapped in Wisconsin, Michigan, and Minnesota and released in Missouri.By 1944 the deer population of Missouri had increased to 15,000 and has now soared over 1 million. Missouri's deer herd is now the best that has ever been recorded. Whitetail deer are 'ungulates' or hoof mammals belonging to the family 'cervidae'. Characteristics distinquishing this group from other hoofed mammals are forked antlers, a 4 chambered stomach, and the absence of a gall bladder. Because whitetail deer are ruminants there able to eat a wide variety of food. Their 4 chambered stomach enables them to break down a variety of plants. Deer stomachs contain microbes that break down cellulose, the fiberous parts of plants,and can ferment carbohydrates thus providing energy and nutrients. Deer are browsing animals that feed on a variety of leaves, twigs, fruits and grains. Deer are selective eaters and have been documented to eat over 600 different types of plants. They like leaves , grasses, acorns and farm crops such as corn, wheat, soybeans and alfalfa. Whitetail deer show a definite selection of plants to eat and consume those which are most nutritious during a specific time of year. During the winter months for example, Whitetails will eat foods that are rich in carbohydrates such as acorns and agricultural grains. Deer also require water in some form daily. The whitetail deer is named for it's most distinct feature, the large white tail which is often seen as the deer bounds away. The color of the deers upper body is generally reddish-brown in summer and gray in winter. It's belly and underside of it's tail are completely white and a patch of white fur also appears on the throat. Deer have long slender legs and small hoofs. During the evolution of hoofs from a 5 toed animal the 1st toe disappeared, the 2nd and 5th toes became dew claws at the back of the foot and the 3rd and 4th toes became enlarged to form the hoofs. As a result, deer walk on their toes or to be more precise, on their toenails. Like human fingernails and toenails, hoofs are made of keratin, a protein that also makes up hair.
The above whitetail deer is a male deer called a buck or a stag, identified because it has antlers.
Female deer called does normally do not have antlers. In summer the coats of both sexes are
reddish brown in color sometimes called a redcoat. This picture was taken during the summer and it shows the reddish coat. Its antlers are growing at this time of year and are covered in velvet. The color pattern of the winter coat is
similar to the summer one but is grayish brown in color and is oten referred to as the blue coat.
The doe above is in her winter coat, notice the darker grayish brown color. The reddish brown coat in summer is quite thin, less than 1/4 inch thick. By august or september deer shed their summer coat and replace it with a thick gray brown winter coat which is sometimes more than 1 inch thick.
The winter coat consists of an under fur and outside gaurd hairs. This dense coat of hair may weigh up to 3 pounds.
Hairs of the winter coat are tubular and somewhat stiff and brittle. The winter skin floats on water and in
the past they've been used as life preservers or floatation devices. Deer can swim and creeks and rivers do not form barriers to deer movements. If food or good cover lies on the other side of a stream a deer will simply swim across to take advantage of what is there. During hot summer days deer will seek shade or wade in bodies of water or just lie on the banks of rivers and streams to cool off.
Glands
Whitetails have 4 sets of external scent glands which are used for communication by smell. Secretions from these scent glands communicate a deers social status, breeding condition and health. The tarsel glands can be recognized by a long dark tuft of hair on the inside of each hind leg. They produce an oily secretion with a pronounced ammonia smell. Other scent glans called the meta tarsals occur on the outside of each hind leg between the ankle and hoof. Interdigital glands occur between the 2 main toes of each foot and secrete a strong offensive odor throughout the year. They act to scent the tracks of deer. Small pre orbital glands are found in front of each eye and are used to scent twigs and branches.
Deer signs
Deer rubs are made by bucks by rubbing their antlers on trees and saplings. Most rubs are thought to be sign posts
made by bucks to advertise their presence. Rubs provide visual clues and scents which inform other dear about the rub maker. Although noone knows for sure these these rubs probably relay information about the deers
social status as well. Scrapes are also sign posts made by bucks. They are used to attract breeding does and
to advertise the presence of the buck. When making a scrape the buck paws at the ground and urinates on the disturbed
soil. Most scrapes are made along deer trails under low branches which are nibbled on and marked with pre orbital
scent glands. Deer have no permanant structure as a home such as a den or a nest, they occupy a variety of habitats for
but prefer areas with enough vegetation for concealment. Deer will often use the same pathway to travel from one location to another and will wear a visible trail. The tracks of deer can often be found in these trails, however there is no way to tell the difference between buck and doe hoof prints. Deer occupy a relatively small territory with an average home range of 1 to 1 1/2 square miles.
Breeding Season-Rut
Bucks often congregate into bachelor groups composed of neighboring bucks during the summer months. Sparring matches are common prior to the break up especially among the younger bucks. Older bucks with previously established dominance normally don't spar during this time. It is through these sparring matches that the bucks establish a social hierarchy. Occasionaly 2 evenly matched bucks get into a sparring match and the battle for dominance is quite serious and could lead to the death of one or both of them. Just prior to the breeding season adult and yearling buck groups break up. An increased production of testosterone triggered by decreasing day length brings about changes in buck behavior and hardens the antlers. The peak of the mating season or rut is around november. This is when adult does are bred. Yearling does are bred about a month later. During the breeding season the necks
of the bucks swell to about twice their normal size reaching a maximum size in mid november. What causes this enlargement is not well understood. The rut is very stressful on bucks and cause them to lose weight during this period.
As breeding activity winds down, testosterone production decreases and they begin to shed their antlers.
Fawns
An adult doe usually has twins but occasionally a single offspring or triplets are born.Each fawn weighs between
4 and 7 pounds at birth. Fawns eyes are open at birth and they can stand shakily 30 minutes after being born. Fawns have a reddish brown coat with white spots. This spotted pattern helps break up the light and aids in camouflaging the fawns where they hide. Fawns will gradually lose their spots between 3 and 5 months of age.
Antlers
Sometimes, incorrectly referred to as horns, deer antlers are shed and regrown each year. Horns on the other hand grow continually and are not shed. Another difference between horns and antlers is that horns grow from the base at the skull and antlers grow from the tips. Deer antlers normally are only found on bucks and are indicators of their social status. Fawn bucks, during their first fall season have a slight swelling on their heads just under the skin called buttons. In some cases fawn bucks may have small unbranched antlers called spikes that have broken through the skin. On yearling bucks the antlers are always clearly visible while some may only show an unbranched main beam at this age, most have more than 1 point. Yearling bucks may have 1 to 6 points on each antler with an average of 6 points on both antlers. As the deer increases in age the antlers become more massive. In general the number of points increases to a total of 10 or 12 but frequently more than 12 will grow. The age of the buck cannot be determined by antler size or the number of points. Following the bucks period of mating and as the buck becomes older the antlers actually decrease in mass. After the rut, the antlers that are shed are found by other animals such as mice, rats, rabbits, and squirrels and are gnawed and eaten. The antlers are consumed by these animals for their protein and other minerals such as calcium. This is why the shed antlers are rarely found during the following spring.
Antler Growth
At the end of the breeding season, bone around the base of the antler is reabsorbed and the antlers become loose and fall off. Antlers are usually shed in January or February. Antler growth usually begins in March or April when the base of the antler called a pedicle located directly on the skull begins to enlarge. The pedicles are permanent fixtures on the deers skull and are the point from which the antler grows. Deer antlers are among the fastest growing tissues known to man, growing an average of 1 to 2 inches per week. During this period a soft skin with short hairs covers the growing antlers giving them a velvety appearance. This stage of antler development is referred to as the velvet stage. The velvet is a sensitive skin filled with nerves and blood vessels that feed the antlers vitamins and minerals necessary to build up the bone inside and to promote normal antler growth. During development the deers antlers are very delicate. Antlers reach their full size around September or shortly before the rut or breeding season. The size of the antlers and number of points depends on a number of factors such as age, genetics, nutrition, quality and quantity of food and hormones. Abnormally shaped antlers are usually the result of an injury to the antlers during it's growth and development period. Antler growth spans a 2 to 4 month period until a ring of tissue forms around the base of the antlers and cuts off the blood supply to the velvet. As a result, the velvet withers, dries up and dies. This makes the antlers very itchy and causes the deer to rub the antlers against shrubs and bushes to remove the velvet and exposes the inner bony antler which is dull initially but will become smooth and shiny with continued rubbing and polishing. The shedding of the velvet takes about 2 to 3 weeks to complete.