Boulders and Bats and Bears, Oh My!

Winter is the best time to count bats. When the cold comes on, the bats of our region disappear into caves and old mines to hibernate — which makes these months the one reliable chance each year to find them, hold still, and count.

Recently, Highlands Field Site Director Dr. Rada Petric, research assistant Adriana Kirk, and I set out to do just that, visiting several of the mines and caves we monitor in partnership with the U.S. Forest Service and the North Carolina Wildlife Resources Commission.

We keep acoustic recorders running at these sites through the year. The devices capture the ultrasonic calls of bats — voices pitched well above anything we can hear — and afterward we run the recordings through software that names the species by sound alone. It is remarkable technology. What it can't tell us is how many bats are actually inside a given cave or mine.

This year's count turned up several Tricolored Bats — among the smallest bats in the eastern United States, a palm-sized animal that, not so long ago, was also one of the most common. Over the last decade, that has changed with startling speed.

Some days, you go underground looking for bats and find something else entirely.

In Clay County, we lowered ourselves into a talus cave — a cavern formed by a jumble of fallen boulders — that we had never surveyed before. Inside, in the dark, lay the skeletonized remains of an American Black Bear.

From the size of the skull and the wear on its molars, we think it was an older female. From the bite marks scored into the skull, we think it was killed by a larger male. It happens: male bears will sometimes attack, kill, and even eat females and cubs, and this one may have been caught while it was denning.