Deaths of millions of bats in U.S., Canada have ecological, economic impacts

I do not like bats. Once, as a college student living in a third-floor apartment with no air-conditioning, a bat landed on me during a hot summer night. I fled my room, shrieking. Even today, on summer nights at my rural home, when bats fly low over my deck, I instinctively duck.

Bats have a bad rep. Think bat and you likely think bat with rabies. Think bat and you likely think dirty bat or bat as vampiric bloodsucker. Think bat and you likely think evil harbinger of doom and destruction. (Okay, that last one’s a tad over the top … but you get the idea.) Bats have fewer defenders than fear-laden critics.

But bats, the only mammal structurally capable of sustained flight, are just creatures with significant ecological — and economic — roles. Hate mosquitoes and other insects? They’re on the nighttime menu for bats. Like bees, many bats pollinate plants and spread seeds. Bat shit (sorry; bat guano) is rich in nitrogen and is a profitable fertilizer. Bats’ ability to navigate in the dark (echolocation) is a subject of significant scientific study.

But in the past five years, up to 6.7 million bats are estimated to have died in 16 states and Canada, the U.S. Fish and Wildlife Service said. Three species face extinction — the little brown bat, the northern long-eared bat and the tricolored bat. A malady called white-nose syndrome is killing them.

Researchers gleaned the estimate by counting bats in winter trips to caves. Bats roost densely, reports Darryl Fears of The Washington Post. So researchers take digital photographs of bats snoring through winter and literally count noses of bats. In 2009, researchers estimated bat deaths at about 1 million. The new figure has alarmed scientists. Says Mylea Bayless, conservation programs manager for Bat Conservation International in Austin, Tex.:

We’re watching a potential extinction event on the order of what we experienced with bison and passenger pigeons for this group of mammals, The difference is we may be seeing the regional extinction of multiple species. Unlike some of the extinction events or population depletion events we’ve seen in the past, we’re looking at a whole group of animals here, not just one species. We don’t know what that means, but it could be catastrophic.

White-nose syndrome, reports Fears, is caused by a fungus called Geomyces destructans. The fungus eats through the skin and membranes of bats. The syndrome was first observed in in 2006 in Howe Caverns near Albany, N.Y., a popular tourist destination down the road from me. Reports Fears:

Since then, biologists in Virginia, Pennsylvania, New Jersey, Vermont, Indiana and other states have returned to caves and mines during the annual winter hibernation of bats and reported alarming numbers of fresh dead to wildlife and gaming agencies.

The extensive demise of bats threatens forest health — and segments of the economy based on forests.

The paper products industry could also be hard hit if pests such as the emerald ash borer proliferate in the absence of bats. Loggers in states such as Vermont “ought to be concerned, but I don’t think the word has really gotten out to these folks,” said Mollie Matteson, a conservation advocate for the Center for Biological Diversity in Richmond, Vt.

“It certainly behooves people concerned about the health of forests — loggers or ecologists — to pay attention,” Matteson said. “But it’s hard to make a direct connection between 7 million bats dead and what happens to forest pests.”

I still don’t like bats. I’ll still duck when they flit over my deck. But none of us should be happy that nearly 7 million have died with no apparent recourse to a cure. The potential extinction of any species — even one that fills many of us with fear and loathing — must concern us.

More on bats:
• white nose syndrome
• the economic cost of losing bats
• the science of bats (video)

photo credit:
• vampire bat by Michael & Patricia Fogden/Corbis

Advertisement