Bats in peril
Pictured: A California Brown Bat … in black and white/
Threats could “SNARL” western bat habitats in near future
Bats are probably one of the most misunderstood creatures on the planet. Their historically bad rap paints them as bloodsuckers that generate public health scares of rabies transmission. In pop culture, they’ve been linked to vampires and vigilante superheroes.
But, according to bat expert Patricia Brown PhD, who presented “Bats in Peril” during this week’s Sierra Nevada Aquatic Research Lab’s popular lecture series, reality is that bats are a special and unique part of our ecosystem. “Apart from their intrinsic beauty, they’re major predators of night bugs,” Brown said. One bat, she went on to detail, can consume as many as 6,000 mosquitoes in one night.
Bats have been key in controlling certain types of pests, aiding in agriculture. They also help pollinate certain types of cactus. Brown, who does mine surveys for various government agencies, said the species is also of major interest to medical science, which is studying the anti-coagulant properties of its saliva.
Other winged animals get more attention from ecological and animal groups, but Brown submitted that the bat is also coming under threat from both man and nature. Major threats to the bat include urbanization, the green/renewable energy sector, mine closures and a curious white fungus, that has led to White Nose Syndrome.
In the case of the green energy market, one obvious threat comes from large wind turbines, which Brown explained can cover an area the size of a football field. They create vortexes that suck in the bats, and can kill them either through contact or by bursting sensitive capillaries in their lungs with radical air pressure changes.
Solar farms are another problem. In addition to man’s encroachment into historic living areas to set up cities and residential developments, large solar array complexes are intruding on foraging areas. “I believe in solar, but I don’t think we need to tear up large chunks of the desert for it,” she opined.
Urbanization has also taken its toll. “We’ve already seen a marked decline in the Red Bat,” Brown pointed out. “In John James Audubon’s day, there were accounts of the skies being red with the bats during migration periods. You don’t see that today.”
White nose, black threat
White Nose Syndrome, as it’s become known, isn’t really about noses turning white. It’s a white fungal growth that invades the tissue of certain types of bats, typically attacking the wings and ears. Under a microscope, it looks almost pretty, rather like a work of Asian art, but Brown said it’s very deadly. “Think of it as form of athlete’s foot that can cover much of the body,” she said. “The bats are very uncomfortable. It awakens them too early from hibernation, causing them to burn off food stores too soon and go foraging for bugs that aren’t out yet.”
In essence the bats starve to death. One problem with the fungus is it’s psychrophillic, or cold-loving, completely at home in the same temperatures bats like for hibernation during winter. First discovered in the U.S. during the winter of 2005-2006, it’s still only found in the eastern part of the country. Brown and other bat experts are concerned about a decided westward migration that could threaten species out west, such as the Little Brown Bat, which is found in the lower 48 states, and has large population in the Eastern Sierra.
Brown said the fungus is the same as one found in Europe, and the working theory is that it’s likely from there. It was, experts think, transported via spore by an unsuspecting tourist or explorer who picked it up in a tour cave somewhere on that continent. Since 2005, it’s been turning up on these shores in coal mines along the Blue Ridge range, in Pennsylvania, and has been moving into the midwest and Oklahoma, and into the south into Alabama.
Bat researchers are concerned about threats to endangered bats, such as the Grey Bat, which is found in only 9 mines and caves in the U.S., and the midwest Indiana Bat. In several caves examined, entire populations have been completely decimated. “No other wildlife disease known has caused this much mortality in such a short time,” Brown laments, adding it has claimed as many as 7 million bats in the northeastern U.S.
Not all bats, however, seem to be affected, though there is no apparent prevention or cure, and no active surveillance method for detecting the disease before onset, short of specific tests in lab settings. Curiously, Big Eared Bats common to Virginia, don ‘t seem immune to the fungus.
Out west, finding bats is the biggest challenge, since data and documentation of bat hibernation sites is much better in the east. In the short term, until research here catches up with the rest of the country, Brown and her colleagues are pushing for more awareness, forging partnerships and developing decontamination procedures.
In the bat cave …
More than half of all U.S. bats roost in mines, which are as prevalent in many parts of the country as caves, and mimic the climatic conditions. Agencies, however, tend to overreact when considering mine closures, be it for economic, environmental or safety reasons.
Mines are fraught with all sorts of dangers to humans, such as dilapidated wood and structures, old dynamite and blasting caps left behind, and rattlesnakes. And humans squatting in mines have led to vandalism and wanton killings of bats by uncaring marauders.
Brown is pushing for more “bat-friendly” gated closures for mines currently used by bats, and better eviction practices for mines that are to be sealed. Bats are “mobile” creatures and can use multiple roosting sites, thus a need for more banding and tracking to more accurately map where bats are living.
Meanwhile, various agencies have started adopting some of Dr. Brown’s mitigation suggestions, but her best recommendation is simply staying out of caves for our safety, and hopefully that of the bats.
Brown, formerly on staff at UCLA, is a partner in Brown-Berry Biological Consulting. The SNARL series concludes this Tuesday with a program on the recent new sightings of the Sierra Nevada Red Fox. The program is free, and starts at 7 p.m. at the Green Church, just off U.S. 395 south of Mammoth Lakes.