Hanging by a leg
COCHECTON, NY — “Can you hear them chittering?” asks National Park Service biologist Jessica Newbern. Chitter, we learn at this lecture earlier this summer, is the language bats use to communicate with one another. Here, at the Cochecton Preservation Society’s (CPS) restored train station, lives a large colony of bats. It’s 7 p.m. The bats are waking up and making plans for their upcoming night.
“They were not invited, but they’re certainly welcome,” says CPS Director Jerry Yavarkovsky of the world’s only flying mammal. (Flying squirrels don’t count because they’re gliders, not true flyers with wings.) As Newbern tells us what she has learned about the furry little creatures, we begin to understand why bats, often regarded by people with fear and aversion, are accepted here.
Having studied the bats of the Upper Delaware region for three years, Newbern has developed an obvious respect and affection for them. “When they’re at rest, bats hang by one leg and cover their faces with the other. How cute is that?” she asks.
There are nine species of bats in the Upper Delaware region. Of those, there are two bat societies: solitary and social. Solitary bats roost singly in trees. Social bats roost together in structures like caves, barns, train stations and post offices. One of the largest bat colonies in the Northeast, upward of 600 bats, lives at the Lackawaxen Post Office, having moved there from their former residence, Zane Grey House, just down the road, when the National Park Service began renovating it to serve as a museum and visitor center.
Newbern tells us that a maternity roost is located on the back of the sign attached to one wall of the station. A maternity roost is a nursery where mother bats breastfeed their young.
The big brown bat, the species that lives at the train station year-round, is particularly hardy. Because bats like warm climates and are active only in temperatures between 55° and 100° Fahrenheit, they must either migrate or hibernate. This colony chooses to hibernate, a remarkable feat, considering that hibernation usually results in a degree of malnutrition that puts bats at the mercy of opportunistic infections. But unlike bats all around them, the bats of the Upper Delaware now show no signs of the disease known as “white nose syndrome” that has decimated bat populations. First detected in 2009, the disease is responsible for a 93% decline in little brown bat populations in the northeast.
Newbern says this may be due to the Upper Delaware’s optimal ecosystem, one so rich in food supply that bats can maintain health through a long winter fast. Although not all bats are insectivores, these are. The Upper Delaware region offers them a variety of aquatic and terrestrial insects from which to choose. Interestingly, they don’t eat the whole bug; they spit out the crunchy exoskeletons, preferring the fleshy abdomens. It was this peccadillo of bats that got “bug freak” Newbern interested in them. Finding dismembered insects got her wondering about a predator that would eat part of an insect instead of consuming it whole.
She discovered that bats are finicky about food and habitat. Temperature, humidity, food supply and fellow creatures must meet with their approval, or they will move on. To discover their surroundings, bats use echo location, a form of sonar, that requires them to get uncomfortably close (“in your face”) to unfamiliar objects, but if you see them as Newbern does, they’re intelligent, highly civilized, social beings.