"We found that in the highly social species that prefer to hibernate in large, tightly-packed groups, the declines were equally severe in colonies that varied from 50 bats to 200,000 bats, which suggests that colonies of those species will continue to decline even when they reach small population sizes," said coauthor A. Marm Kilpatrick, assistant professor of ecology and evolutionary biology at UC Santa Cruz.
Trends in the declines of different bat species since the emergence of white-nose syndrome support these predictions. As populations get smaller, the declines tend to level off for species that roost singly, but not for socially gregarious species.
Surprisingly, however, one highly social species is bucking the trend. The little brown bat, one of the most common bat species in the northeast, appears to be changing its social behavior, going from a species that preferred to roost in dense clusters to one in which most bats now roost apart from other bats. "Our analysis suggests that the little brown bats are probably not going to go extinct because they are changing their social behavior in a way that will result in them persisting at smaller populations," Kilpatrick said.
Another gregarious species, the Indiana bat, continues to hibernate mostly in dense clusters and will probably continue to decline toward extinction, according to Langwig. "Since the appearance of white-nose syndrome, both species have become more solitary, but the change is much more dramatic in the little brown bats," she said. "We now see up to 75 percent of them roosting singly. For Indiana bats, only 8 to 9 percent are roosting alone, which does n
|Contact: Tim Stephens|
University of California - Santa Cruz