Warm weather is returning and so are Delaware's bats

Delaware is home to eight species of bats, several of which have begun their annual move from winter hibernation sites to summer maternity colonies.

Female bats return pregnant to the colonies where they congregate to give birth and raise their pups. In Delaware, these colonies can often take up residence in barns, garages, attics and homes.

In Delaware, bats feed at night on insects, many of which are pest species like mosquitoes. Some eat moths and beetles that damage crops. “They’re providing us with a valuable and free service, so it’s to our benefit to have them around,” said wildlife biologist Holly Niederriter of  the Department of Natural Resources and Environmental Control's Division of Fish and Wildlife.

A study published in Science magazine’s Policy Forum suggests bats could be one of the most economically valuable groups of wildlife to North American farmers, saving farmers at least $3.7 million annually by reducing the amount of pesticides needed.

Even though bats play an important role in the ecosystem, they are often unwanted visitors inside homes, garages and other outbuildings.  For a resident who has bats roosting in an undesirable location, excluding bats from the building may be warranted.

For a list of permitted nuisance wildlife control operators who can conduct bat exclusions and to review best management practices for excluding bats, as well as more information on the Delaware Bat Program, go to www.dnrec.delaware.gov/fw/bats. The Delaware Bat program is also on Facebook at facebook.com/DelawareFishWildlife.

In spring, it is crucial that bat exclusions be completed before May 15, when female bats typically settle into their colony sites and begin giving birth. If done after that date, flightless young may be trapped inside buildings and permanently separated from their mothers, without whom they cannot survive.

DNREC’s Division of Fish and Wildlife biologists are seeking volunteer bat spotters to help in locating and counting the state’s non-nuisance bat colonies. The Delaware Bat Count is a statewide research study of bat populations, breeding activity and the overall health of the bats that inhabit thestate. The bat program is always looking for reports of new bat colonies.

To report a bat colony, or for more information on volunteering as a bat spotter or on bat exclusions, contact Niederriter or Sarah Brownlee-Bouboulis, at 302-735-8674, or by email at sarah.brownlee@state.de.us.