The state Game Commission reported that hunters killed an estimated 343,110 white-tailed deer during the 2012-13 deer seasons. The harvest included 133,860 antlered deer and 209,250 antlerless deer. Hunters are the greatest predators of Pennsylvania deer.
As the gun deer season approaches, there's a tendency to ignore other forms of deer mortality. But deer must deal with a variety of natural predators.
Predation is the most interesting mortality factor because it involves large familiar animals. Though rarely observed and difficult to quantify, predation is a natural means of controlling deer populations.
Where deer coexist with wolves or mountain lions, deer are big predators' most important prey. In Pennsylvania, however, other predators fill the vacant niche once occupied by cougars and wolves.
Black bears rarely fail to take fawns whenever they encounter them. Fortunately this window of vulnerability is relatively brief, so bear predation is not significant.
Coyotes are the top natural deer predator in the East. Some studies have shown that coyotes are responsible for up to 80 percent of fawn mortality, and small packs of coyotes chase and kill some adult deer. In fact, most deer killed by predators are fawns, sickly or aged adults, or deer exhausted from slogging through deep snow. Only mountain lions and wolves routinely take healthy adult deer, and even they prefer the young, sick or weak.
The list of other predators that can take deer in Pennsylvania is short. Domestic dogs sometimes chase deer to the point of exhaustion -- one study from the 1970s estimated that dogs killed 500 to 1,000 deer annually in Pennsylvania.
Bobcats can take deer in deep snow, and they sometimes attack deer on beds at night, but their total impact is minor. Fishers probably take a few fawns, but as a recently reintroduced species, fishers are too few to be an important factor. And foxes are too small to be a serious predator of anything but newborn fawns.
The white-tailed deer's reproductive potential is its saving grace. It's a polygamous species -- a few males can service many females, which typically have multiple twin-bearing years. Deer can sustain heavy losses from predators and hunters and still maintain a stable or even growing population.
Biologist, author, and broadcaster Scott Shalaway can be heard 8 to 10 a.m. Saturdays on 1370 WVLY-AM (Wheeling) or online at www.wvly.net. Or visit his website www.drshalaway.com or contact him directly at firstname.lastname@example.org or 2222 Fish Ridge Road, Cameron, WV 26033.