It’s hard being a bat, but people can help a struggling species

As dusk descends in the spring and summer, Delawareans listening closely can start hearing the faint clicks of one of the state’s best mosquito managers.

It is prime time for bat activity as the weather begins to warm.

And while the world’s only flying mammal might get a bad rap from movies and vampire legends, they can put a dent in the populations of pesky, stinging, biting bugs that can make warm summer evenings miserable.

“They’re a critically important part of the world’s biodiversity and they don’t really get the respect they deserve overall because people have biases toward them,” said Holly Niederriter, a wildlife biologist with the state Department of Natural Resources and Environmental Control’s Division of Fish and Wildlife. “And they mean us no harm.”

These winged pest controllers have been having a hard time themselves over the last decade. The eruption of white-nose syndrome, a potentially fatal disease caused by a certain type of fungus, has decimated populations across the country.

At least nine species in North America — five of which are known to or suspected to frequent Delaware — have been hit hard by the disease since it first appeared in New York in 2006.

In Delaware, the little brown bat was hit the hardest when white-nose syndrome was confirmed in 2012. That species, along with the northern long-eared bat, are endangered in the First State.

“We did have a couple colonies of little brown bats and we tracked them very closely,” Niederriter said. “And they all went to zero. We lost all of them.”

That’s bad news for people prone to mosquito bites. A little brown bat can eat its own weight in insects every night — the equivalent of a person eating about 100 Big Macs at once, she said.

Niederriter said it is nearly impossible to tell how many bats are still thriving in Delaware, but the count is likely in the thousands or more. Big brown bats are the most commonly spotted among the eight species known to live in the First State in leaf piles, attics, barns and historical forts.

“There are a lot of ways to mitigate the losses by trying to protect the bats,” she said. “There’s everything from genetic manipulation to vaccines for bats [to fight white-nose syndrome], but as far as I can tell, there’s nothing that can solve the problem once and for all. The best we can do is save those that are left and possibly to rebuild some of the others.”

Because most bats only have one pup each year, it will take a while for those populations to rebound. That makes it important for people to not only help document how many bats there are, but also make sure people do not cut young, vulnerable pups off from their mothers before they can fend for themselves.

To more closely and accurately track how these extraordinary pest managers are doing, the state Department of Natural Resources and Environmental Control relies on citizen volunteers to count known and new colonies of bats living across the state.

Sarah Bouboulis, a habitat project specialist at the Partnership for the Delaware Estuary, said it’s peaceful sitting in a camping chair on a perfect spring evening, carefully counting the curious creatures as they emerge for meal time.

“Then you just sit back and watch,” she said. “Our bats here are really cool, but if you look worldwide at bats, they’re even cooler. They fill all the realms.”

Some crawl on the ground instead of flying, like the lesser short-tailed bat in New Zealand. Some have fuzzy faces that are so cute they seem like a cartoon, like the flying foxes found in more tropical places. Some are known to go fishing for their food, like the fisherman bat of Latin America.

On July 26, Bouboulis will share some information at an event at the Mt. Cuba Center about how bats benefit local ecosystems, especially gardens and agricultural lands. Some studies have estimated bats save farmers more than $3 billion each year in pesticides by eating crop-damaging bugs.

While some people might think of bats as flying rats, they’re actually more closely related to humans and primates than rodents, Niederriter said.

“People imagine that bats go out and fly all night long,” she said. “They don’t. It’s really a lot of work to fly when you’re a mammal. It’s hard to be a bat.”

Bat experts like Niederriter encourage people to consider holding off on kicking bats out of their attics and barns, at least until the end of August so the pups have time to grow and take flight.

If exclusions – when people install one-way devices to let bats get out of attics but not back in – are done before the pups have time to grow, it can be devastating for them and their mothers.

“If you do that while there are flightless pups back in the barn, the moms can’t back in,” Niederriter said. “It’s horrible for the babies and it’s horrible for landowners, too.”

When bats aren’t hunting bugs, hibernating or taking naps, females are spending most of their energy being really great moms. They spend about four weeks feeding frequently to maintain their own weight while feeding their babies.

In a colony of hundreds of bats, a mother can recognize her own pup's cries and go right to it despite the darkness. And Neiderriter says she has seen cases where bat moms will intensely stare down people if they come anywhere near their babies.

Most bat moms give birth to only one or two pups each year, which are born hairless and helpless. Spring and early summer are when pregnant bats give birth, meaning it is the least ideal time to force them to find a new home if they have settled into an attic, barn or other cave-like place frequented by people.

“With an exclusion, a mom will do everything she can to reach her pup,” she said. “Bats are really good moms. And like humans, they devote a lot of energy to a small number of offspring.”

To report bat colonies to volunteer to become a bat monitor, call (302) 735-3600 or go to www.dnrec.delaware.gov/fw/bats. Learn more about bats at batweek.org. 

Contact reporter Maddy Lauria at (302) 345-0608, mlauria@delawareonline.com or on Twitter @MaddyinMilford.

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