Helping Connecticut's Bats

Updated.

White-nose Syndrome continues to ravage bat populations. The Hartford Courant reports today:

It's the grim news that wildlife biologists have dreaded all winter: Officials from the state Department of Environmental Protection will confirm this morning that population counts of hibernating bats show that they continue to be decimated by the disease known as white-nose syndrome, and that some species might even be threatened with extinction.
"The numbers are devastating for Connecticut bats," said one DEP official. "The onslaught of white-nose just won't stop."

Since White Nose Syndrome was discovered in a New York cave in February 2006, bat populations throughout the northeast and several mid Atlantic states have been devastated with more than one million bats dying from what researchers believe is linked to this fungus.

The fungus found on the bats has been identified as Geomyces destructans and typically appears on the faces and wings of hibernating bats, but is virtually never seen on the bats once they leave the caves. It is not known how the fungus adversely affects the bats or if it truly is the cause of their deaths. Hibernating bats commonly awaken during the winter to hydrate themselves with moisture that condenses on their fur. However, affected bats awaken more frequently which uses up much of their fat reserves.

Consequently, in mid-winter the bats become hungry and awaken to hunt for food. Of course, there are no insects flying in January or February and the bats generally die from starvation or freeze to death.
WNS has affected all five of our cave bat species here in Connecticut. Since these cave bats are long-lived animals (some can live 20 years or more) and their reproductive rate is slow – usually one pup per year, to recover from the more than one million bats that have already succumbed to WNS, will take many years. Until researchers understand the disease better, little can be done to mitigate it.

Researchers are hard at work, however, and you can help. The Connecticut DEP Wildlife Division biologists are interested in the location of summer bat maternity roosts where female bats gather together to give birth and raise their young. By conducting at least two bat surveys, your data can be added to that of other citizen scientists and provide researchers with more information than they could gather on their own. Wildlife Division biologists may want to conduct extended research at selected roost sites. The time that it will take to find the roost exits, count the bats and record your findings should only take a few short hours for the entire process. You do not need to be able to identify which species of bat you are counting.

The bat roost surveys consist of at least two counts of bats leaving the roost for a night's hunting. One count should be done between the last week of May and the third week of June before pups begin to fly. This count will help determine the number of females in the roost. The second count should be done between July 4 and July 31 after most pups begin to fly. This count will help determine the reproductive rate of the roost.

If you want to help researchers with summer bat counts, the complete protocol for the surveys and the survey forms can be found here.

For more information contact licensed bat rehabilitator Linda E. Bowen at linda@cmsincorporated.net or CT DEP Wildlife Division biologist Christina Kocer, christina.kocer@ct.gov.

Updated

The Connecticut DEP reported today on the winter bat hibernacula surveys:

Jenny Dickson, DEP Supervising Wildlife Biologist, said, "White Nose Syndrome continues to have a catastrophic effect on bats. Just three short years ago, one of Connecticut’s largest hibernacula had over 3,300 wintering bats. This year fewer than a dozen remain—all but one showed active signs of WNS. The outlook for their survival is grim.”

The DEP says visits to other winter hibernacula – caves and mines where bats hibernate– revealed similar mortality rates. Another large site showed a 95% decline in bat numbers since a winter count in 2007. The only positive note from the 2010 surveys was that only three of the remaining bats at that site showed visible signs of the fungus....

Dickson said the DEP is asking the public to report any known summer bat colonies by calling (860)675-8130 or via email to Wildlife Technician, Christina Kocer at christina.kocer@ct.gov . As bats continue to return to maternity sites and summer roosts, the agency would like to hear from people about changes in the number of bats they are seeing or even about bat colonies that once existed and do not return to their previous homes. [Emphasis added.]

Image: Little Brown Bat with White-nose Syndrome by Marvin Moriarty/USFWS