By TIM FAULKNER/ecoRI News staff
This photo of a big brown bat, not to be confused with the little
brown bat, was taken at the Bat Lab run by James Simmons at Brown University.
There are bats in Rhode Island. They inhabit barns in South
County, high-rises in Providence and mansions in Newport. The problem is there
are just a lot fewer of them than there were a decade ago, according to local
bat experts.
Matt Grady, owner of animal removal company BatGuys Wildlife
Service, has collected bats from attics and chimneys across Rhode Island and
eastern Massachusetts for almost two decades. He began seeing their numbers decrease
significantly with the onset of white-nose syndrome.
The disease has decimated as much as 90 percent of migrating bats
as they wintered in caves and abandoned mines in upstate New York, Vermont and
Canada. The death of millions of bats has significantly reduced the
once-familiar little brown bat in the region. Other less-common species, such
as the Eastern red, hoary and silver-haired bats, are all but gone, according
to Grady.
“We used to have a healthy population of little brown bats ... but they were wiped out by white-nose syndrome in 2006-2007,” he said. “I haven't seen one since.”
The little brown bat, which is about the size of a field mouse and
weighs less than a half-ounce, is considered a country bat found in rural South
County, along the Connecticut border, and in the Foster and Glocester area.
They were most abundant in Tiverton and Little Compton.
Charles Brown, a wildlife specialist with the Rhode Island
Department of Environmental Management (DEM), said little brown bats have been
hit hard by white-nose syndrome, but he knows of at least a dozen colonies that
summer in Rhode Island barns.
Since 2010, Brown has examined the bats tested for rabies by the
state Department of Health and has only seen one little brown bat among about
1,500 collected.
“There is no question the number of little brown bats that spend
the summer months in Rhode Island has declined,” he said.
University of Rhode Island professor Peter August said white-nose
syndrome has “taken one of our most common bats and turned it into one of our
rarest.”
August, co-chair of URI’s environmental science graduate program,
said he’s hopeful that surviving little brown bats will have offspring that are
immune to white-nose syndrome. Both he and Brown have observed that the
dramatic die-off of little brown bats may have hit its low point and the
population could, at least, be stabilizing.
“The reality is it’s going to take a long, long time for anywhere
in the Northeast to return to as we had pre-white-nose syndrome,” August said.
Another problem for bats, as well as birds, are wind turbines.
Large turbines are often built along bat migration routes, where bats mistaken
them for trees. The bats are struck by the blades or implode from the sudden
change in air pressure. A 2013 study in the journal BioScience estimated
that wind turbines kill some 600,000 bats annually.
“It’s becoming a real issue as people start to study this,” Brown
said. Wind energy, he said, “may not be as green as we think it is.”
Bats are also suffering from a loss of habitat. Smaller bats
likely flourished centuries ago when much of southern New England was wooded
and swampland. Trees provided shelter and swamps were rife with mosquitoes —
the main food for smaller migratory bats like the little brown bat.
The influx and proliferation of houses and other structures,
however, have proven suitable for bats that overwinter, such as the big brown
bat.
Contrary to its name, the big brown bat is not much larger than
the little brown bat, weighing less than an ounce and with a body size of 4-5
inches. However, they have a broader diet than migratory bats, eating moths,
beetles and other insects. As a result, the big brown bat is now the most
common bat in the region and appears to be thriving. They can be found in
nearly any structure.
Bats may be a nuisance to homeowners, but they are valuable for
the environment. They eat a lot of mosquitoes and bugs that harm crops. For
example, swarms of bats provide valuable pest-control for cotton and corn crops
in Texas and Oklahoma.
“There are really important to controlling our mosquito
population,” said Nicole Souza, who leads bat-watching tours for the Norman
Bird Sanctuary in Middletown.
Despite its size, Rhode Island conducts a lot of bat research.
James Simmons, a professor of neuroscience at Brown University, has studied
bats since 1965. His work, much of it funded by the Office of Naval Research,
focuses on the auditory system of bats and its application to sonar. He’s been
featured, along with fellow Brown University professor Sharon Swartz, who
studies bat flight, in a bat documentary.
Bats are the largest group of mammals in the world. Here are some
facts about local bats and bats in other regions:
There are about 1,300 bat species in the world.
About half are threatened or endangered, largely because of habitat loss,
disease and wind turbines.
All bats found in New England eat night-flying
insects such as mosquitoes, moths, beetles and even wasps. They typically
consume 2,000 or more insects a night. Some tropical bat species eat fruit and
nectar and are important pollinators. Other non-New England species feed on
frogs, small fish and rodents.
As
insects disappear
when it gets cooler, so do bats. Migratory bats fly south or head north to
winter in mines and caves.
Bats are the only mammal capable of flying, which
they do mostly at night while feeding. For centuries, inventors and scientists
have tried, and mostly failed, to replicate the unique flying ability of bats.
Female
bats give
birth to one pup annually. About 90 percent of newborn bats die in their first
year. Those that survive live up to 40 years.
In the past 50 years, fewer than 40 people have
contracted rabies from wild bats. Fewer than 1 percent of bats have rabies.
Still, health officials recommend that any bat found in a home get tested. Click here for
more safety tips.
Flat,
wooden maternity
roosts are ideal for attracting bats. There are many in Rhode Island, including
three at the Norman Bird Sanctuary. They are easy to build and typically host
150 to 200 bats.