Bats "Socially Network" to Avoid Roost Destruction

No, bats haven't suddenly learned how to use Twitter or Facebook, but researchers have discovered that endangered Indiana bat colonies may be using complex social connections to ensure that they always have a place to bed down, even if their roosts are destroyed by disease or human interference. 

According to a study published in the journal PLOS One, Indiana bats may "socialize" with one another as they forage at night, networking closer and overlapping roosting locations in attempts to rebuild a colony that could have been broken up by roost destruction.

"Social dynamics are important to bat roosting behavior," study co-author Alexander Silvis said in a recent statement. "And now, looking at results of a study of roosting and foraging activity in a new light, we have evidence that Indiana bats make social contacts during foraging."

Silvis and his colleagues obtained this new perspective on bat social networks after closely analyzing data from radio-tagged bats in 2009 and 2010. Forty-nine bats were tagged in all, belonging to maternity colonies.

By tracking tag signals, the researchers were able to map a network of connections between roosts.

Interestingly, the researchers found that roosting locations in 2009 compared to 2010 were far more wide-spread and isolated. However, in 2010, the roosting locations were closer together and more prone to overlap in foraging locations, allowing for members of different roost locations to communicate with one another as they forage.

The researchers now theorize that this practice is occasionally done in bat colonies to reestablish social networks and ensure the strength and wholeness of the entire colony.

W. Mark Ford of the Virginia Cooperative Fish and Wildlife Research Unit, who advised Silvis, said that this is a rather startling discovery capable of explaining how colonies can bounce back from apparently disastrous roosting loss - such as seen when the disease white-nose syndrome swept through bat populations.

"The study highlights a level of complexity in both roost and roosting area use that has not been previously described and raises questions about the resiliency of Indiana bats to roost loss," Ford said.

"An improved understanding of Indiana bat social structure and roosting behavior could greatly benefit efforts to minimize impacts of human land use on the species and provide insight into habitat management efforts," he added.