Team People reports an unusually high number of losses lately for mammals on other teams — in the form of roadkill, to be precise. But people don’t seem to be driving more aggressively or less mindfully. So what’s the explanation?
Acorns! Or rather the dearth of acorns throughout most of Virginia this fall, according to biologists and other scientists who study such things.
Rich in fat, soluble carbohydrates and energy, acorns as a food source have “extensive and complex” impacts on wildlife populations, in the words of Gary Norman, of the Virginia Department of Game and Inland Fisheries. Numerous factors, including weather, insects and disease, can “influence acorn development from the time of flower initiation to acorn maturity.”
White oaks produce acorns in one growing season, whereas red oaks require two — which makes it tougher to attribute low acorn production by both groups in one season to specific weather events in a single year.
Whatever the cause, the scarcity of this important wildlife food leads to hungry animals ranging far and wide — and across highways — in search of food. Near Roanoke, numerous bears have been struck and killed this fall by motorists, as especially sows with cubs seek to fatten up for winter inactivity. Here in Rappahannock, dead deer, skunks, possums and squirrels are splattered everywhere.
Acorns are one of the state’s most common types of “hard mast,” a term that includes other tree nuts as forest food sources such as hickory and walnut. The scarcity of acorns this fall might have delayed the deer rut according to one hunting expert, because bucks and does have been so lean. Deer are also now more likely to leave forested areas to browse vegetation because without acorns the woods provide little more than cover.
Interestingly, last year was a bumper crop of acorns. And forestry department research has shown that “the inherent cycles between bumper crops and light crops may be an adaptation to allow the trees to restore their resources following a bumper crop.”
Ecosystems encompass exceedingly complex and often incalculable interactions, of course. Everything impacts something else, and any change brings both temporary “winners” and “losers.” For example, acorns are also an important food source for the white-footed mouse, which in turn is an important target in the life cycle of the deer tick. So next summer should see a lower incidence of Lyme disease!
So say the human experts.