White-tail deer are the most abundant large game species in North America; the whitetail population is largest in Texas, where an estimated three to four million of the deer reside. Their characteristic tails are held erect when fleeing to display the white underside; the rest of their body is reddish-brown in summer and grayish-brown in winter. Fawns less than six months of age have bright white spots scattered on their coats. Adult bucks can attain lengths of over six feet and weight up to three hundred pounds; adult does tend to be smaller. Like mule deer, white-tail bucks grow a new set of antlers every year, shedding the old ones after the rut (breeding season) is over. Whitetail antlers are comprised of one main beam per antler; in mature bucks, each beam may have three or more tines sprouting from the beam.
White-tailed deer are generalists and can adapt to a wide variety of habitats. The largest deer occur in the temperate regions of Canada and United States. The Northern white-tailed deer (borealis), Dakota white-tailed deer (dacotensis), and Northwest white-tailed deer (ochrourus) are some of the largest animals, with large antlers. The smallest deer occur in the Florida Keys. Although most often thought of as forest animals depending on relatively small openings and edges, white-tailed deer can equally adapt themselves to life in more open prairie, savanna woodlands, and sage communities as in the Southwestern United States and northern Mexico, These savanna-adapted deer have relatively large antlers in proportion to their body size and large tails. Also, there is a noticeable difference in size between male and female deer of the savannas. The Texas white-tailed deer (texanus), of the prairies and oak savannas of Texas and parts of Mexico, are the largest savanna-adapted deer in the Southwest, with impressive antlers that might rival deer found in Canada and the northern United States. There are also populations of Arizona (couesi) and Carmen Mountains (carminis) white-tailed deer that inhabit montane mixed oak and pine woodland communities. The Arizona and Carmen Mountains deer are smaller but may also have impressive antlers, considering their size. The white-tailed deer of the Llanos region of Colombia and Venezuela (apurensis and gymnotis) have antler dimensions that are similar to the Arizona white-tailed deer. Whitetail deer eat large varieties of food, commonly eating legumes and foraging on other plants, including shoots, leaves, cacti, and grasses. They also eat acorns, fruit, and corn. Their special stomach allows them to eat some things that humans cannot, such as mushrooms that are poisonous to humans and Red Sumac. Their diet varies in the seasons according to availability of food sources. They will also eat hay and other food that they can find in a farm yard. Whitetail deer have been known to opportunistically feed on nesting songbirds, field mice, and birds trapped in Mist nets. The white-tailed deer is a ruminant, which means it has a four-chambered stomach. Each chamber has a different and specific function that allows the deer to quickly eat a variety of different food, digesting it at a later time in a safe area of cover. The Whitetail stomach hosts a complex set of bacteria that change as the deer's diet changes through the seasons. If the bacteria necessary for digestion of a particular food (e.g., hay) are absent it will not be digested. There are several natural predators of white-tailed deer. Gray wolves, cougars, American alligators and (in the tropics) jaguars are the more effective natural predators of adult deer. Bobcats, lynxes, bears and packs of coyotes usually will prey on deer fawns. Bears may sometimes attack adult deer while lynxes, coyotes and bobcats are most likely to take adult deer when the ungulates are weakened by winter weather. The general extirpation of natural deer predators over the East Coast (only the coyote is now widespread) is believed to be a factor in the overpopulation issues with this species. Many scavengers rely on deer as carrion, including New World vultures, hawks, eagles, foxes and corvids (the latter three may also rarely prey on deer fawns).
The optimal time to view whitetail deer is during the summer, after the fawns have been born and the bucks are no longer pressured by the biological drive to breed. Abundant throughout the state, whitetails can be seen at most Texas parks.