Whitetails are skittish, forever on alert for predators. Main predators of deer are mountain lions, wolves, coyotes and wild dogs. Whitetails rely on their keen senses of smell, sight and hearing to detect predators. Upon sensing trouble, a deer's main defense is to run. Whitetails are one of the fastest animals in the forest, so this often works out. When cornered, bucks undoubtedly try to ward off predators with their antlers. Deer are good swimmers and don't hesitate to take to water to evade predators. Humans are a threat to deer. Poachers, for example, kill many deer illegally each year. Hundreds of thousands of deer are hit by cars annually. Deer are susceptible to many parasites and diseases. A disease can spread like fire through a herd and kill many deer. Generally, outbreaks are localized and populations usually rebound in a few years.
Although mountain lion live primarily in the West, where mule deer are abundant, whitetail deer are still a staple food in some regions. The strong mountain lion easily kills a deer once it is able to stealthily approach it.
Wolves hunt in packs rather than alone. The slow wolf has a hard time catching a healthy deer, so its diet consists mostly of weak and malnourished deer.
Although a coyote's hunting patterns are similar to that of the wolf, they are smaller animals, which limits the amount of deer they can catch. They are content being scavengers, although in times of need they will actively hunt. Coyotes usually feed on weak and malnourished deer, as well as fawns.
There are many other predators which do not pose a huge threat to deer. These include the bear, the bobcat, the wild dog, and the alligator.
Poaching is a serious problem. Poaching is the illegal hunting of deer out-of-season, at night, or in restricted areas such as forest preserves. Some poachers kill to keep the deer away from their crops, or because they need the meat. Others poach simply because they consider it "fun". No matter what the reason, poaching shines a negative light on hunting and is detrimental to all wildlife populations and habitat. If you know or suspect someone is poaching, please contact your local police or DNR office immediately.