White-nose syndrome still devastating bats and challenging scientists

A healthy Virginia big-eared bat in WV
Credit: Jeff Hajenga, WVDNR

In an effort to conserve and research the endangered Virginia big-eared bat, the Smithsonian’s National Zoo took in 40 bats in November 2009. The goal was to establish a security population and to scientifically develop husbandry practices in a subspecies that researchers have not attempted to conserve before. 

According to a press release, “The possible extinction of an endangered subspecies, and the loss of its essential role in local ecosystems, were the reasons the National Zoo accepted the high-risk project.” 

The task proved to be difficult indeed. The Smithsonian recently reported that, of the 40 original bats, only 11 remain. The greatest difficulty the researchers faced was training the bats, which eat insects while in flight in the wild, to eat mealworms from a bowl. Others did not  adapt well to captivity and ceased all grooming behaviors; the resulting inflamed skin led to deadly infections.

Says David Wildt, head of the National Zoo’s Species Survival Center in the release:   

We expected some of the feeding challenges. But we were surprised to learn how sensitive this particular subspecies of bat is. Even the smallest change in environment or husbandry practices seemed to affect the ability of the bats to adapt to their new environment.   

The researchers are hopeful, however, that enough of the bats remain to create a sustainable population. They also report they were able to learn from the incidents and can use this knowledge to better develop precautionary strategies.   

These endangered bats, and others, are at-risk for developing white-nose syndrome, a disease characterized by a white, cold-loving fungus that depletes bats’ fat reserves and causes them to starve. Conservation is currently one of the only options available  to preserve bat populations.   

However, scientists recently proposed another method of slowing population declines, at least while researchers work to find a cure. In the March issue of Frontiers in Ecology and the Environment, Justin Boyles and Craig Willis outline a model designed to artificially warm localized areas during the winter to reduce energy expenditure. While it has not been tested, they predict an increase of 28°C could improve bat survival by up to 75%.   

Read more on white-nose syndrome at http://www.esa.org/esablog/ecology-in-policy/white-nose-syndrome-forces-cave-closings/ and listen to  “Combating White-nose Syndrome” on Beyond the Frontier.

http://www.flickr.com/photos/usfwsnortheast/ / CC BY-ND 2.0

Boyles, J., & Willis, C. (2010). Could localized warm areas inside cold caves reduce mortality of hibernating bats affected by white-nose syndrome? Frontiers in Ecology and the Environment, 8 (2), 92-98 DOI: 10.1890/080187