Bats are pretty impressive critters. They are notorious for carrying viruses like Ebola and SARS, but somehow avoid getting these diseases themselves. They are the only mammal that can fly, and they live far longer than other mammals their size. What’s their secret? Researchers in Australia sequenced two different bat genomes and found that these unique bat characteristics are not only genetically linked, but may help in the treatment of human diseases.
The healthy little brown bats roosting close to the bat
with white-nose syndrome risk infection with the fungus
The deadly fungus that causes white-nose syndrome is sweeping through North American bat populations, and little brown bats are adapting their behavior to avoid it. Although these bats typically clump together in large groups, they are now spreading out to roost separately, a change in behavior that may be helping the bat populations rebound. So what does a bat-killing fungus have to do with human prejudice? The bats’ trick of splitting up to survive contagion may also have led humans to divide into tribes and respond hostilely to members of different, potentially diseased groups.
In a post on Scientific American’s Guest Blog, biologist Rob Dunn writes about the link between infectious diseases and human prejudice.
What’s the News: Bats have to use twice as much energy to fly when they’re wet as when they’re dry, a new study in Biology Letters found, which may help explain why many bats refrain from flying in heavy rain.
What’s the News: Bats are an economic boon worth approximately $23 billion per year, and possibly up to $54 billion, to U.S. agriculture, a study in today’s issue of Science estimates. Their voracious appetite for insects—a colony of 150 brown bats eats about 1.3 million pesky, crop-chomping bugs each year—means that bats function as effective, and free, natural pesticides.
In the realm of meteorology, bats, birds, and insects are usually considered “animalas non grata,” since they create unwanted noise in the Doppler radar readouts used to study storms. But now, thanks to better radar station networking and the sharing of unfiltered data, ecologists have realized that these radar systems can be used as powerful animal tracking tools.
At last week’s American Association for the Advancement of Science meeting, researchers Thomas Kunz, Winifred Frick, and Phillip Chilson explained how Dopplar data can be used by ecologists. They call their new discipline aeroecology.
This melding of meteorology and ecology started with an “Aha!” moment:
“Dr Kunz and I were meeting Dr Chilson about a year ago over breakfast and they kept talking about the ‘QPE’, and finally I asked what it is,” Dr Frick told the meeting. It stands for quantitative precipitation estimator — a numerical method to measure how much rain there is in a storm front. “I paused and said, ‘you can estimate the number of raindrops in a raincloud? Do you think we could estimate the number of bats in a bat cloud?’” To calibrate their experiment, the team took a bat into a chamber where the degree to which it reflects radio waves could be measured. “From those measurements and using radar, we’ve been able to adapt those QPE measurements to a ‘QBE’ – a quantitative bat estimator,” Dr Frick said. [BBC News]
Some plants want ample water and sunshine. The plant Nepenthes rafflesiana, however, desires the droppings of Hardwicke’s woolly bats.
The carnivorous plant and the key-sized tiny bat live on the Indonesian island of Borneo, where their unusual arrangement has blossomed. Scientists who placed trackers on the backs of the bats found that they nap away their days nestled in the pitcher of this pitcher plant, and they use it as their personal commode. That’s just fine for the pitcher plant, which doesn’t trap as many bugs as its relatives, but makes up for it by deriving one-third of its nutrients from bat excrement.
“It’s totally unexpected,” said Ulmar Grafe, an associate professor at the Universiti Brunei Darussalam who led the study. “There’s a lot of animal-plant mutualisms, but this one is where the animal gives a nutrient to a plant. Usually it’s the other way around.” [Reuters]
You might think it’d be dangerous for bats to lay around in a plant’s pitcher, where they could plummet into the gooey nectar the plant uses to trap and eat insects. But, in fact, the pitcher is shaped just right so that the bats can’t fall through. Says Grafe:
The continued onslaught by white nose syndrome against North America’s bats is one of the stories of the year—number 13, in fact, on DISCOVER’s Top 100 of 2010. But some help soon could be on the way in the form of Endangered Species Act protection. Earlier this month, a group of conservationists and scientists filed an emergency petition with the United States Fish and Wildlife Service to list the little brown bat under the act.
Emergency listing for a species does happen, but not very often, says Ann Froschauer, national white-nose syndrome communications leader for FWS. “Given the urgency of white-nose syndrome and recent information about predicted declines in little brown bat populations, the Service is committed to quickly reviewing scientific information, both published and provided by organizations such as these, in assessing the status of little brown bats and other bat species affected by WNS.” [Scientific American]
Listing the bats as endangered could force government action to protect them, including increased funding and the designation of critical habitat.
80beats: Search for Long-Lost Amphibians Finds Its First Three
80beats: The “Lost Frog” Quest: Researchers Seek the World’s Rarest Amphibians
80beats: Saving the Rainforest Could Make Economic Sense
80beats: Papua New Guinea’s Forests Falling Fast
DISCOVER: 10 Science Hotspots–Where Mother Nature Reveals Her Secrets
When we last covered little brown bats it was with big bad news: A study in Science suggested that white nose syndrome could kill enough of the bats to make them regionally extinct in many parts of the United States by 2020. This week, though, brought a glimmer of hope. Scientists at the New York State Department of Health led by Vishnu Chaturvedi say some anti-fungal drugs work against the mysterious fungus causing the bat die-off.
They tested six strains of the novel fungus against drugs already used to treat people and animals such as cats and dogs for ailments ranging from athlete’s foot to life-threatening infections. “We found that two major classes of antifungal drugs have very good activity” against the bat germ, Chaturvedi reported Sunday in Boston at a meeting of the American Society for Microbiology. The drugs include fluconazole, the most widely used antifungal drug, which is sold as Diflucan by Pfizer Inc. and in generic form. Four other drugs also seem highly effective, Chaturvedi said. [AP]
Five years ago, there were six and a half million little brown bats in the Northeastern United States. In 2020, there may be next to none.
This week in Science, a study models the collapse in bat populations brought on by white-nose syndrome, which was first found in 2006 and is seemingly caused by a nasty fungus. Researchers think that bats with the affliction awaken too early from hibernation, messing up their natural cycles and draining their reserves of energy. A team led by Winifred Frick checked the math on bat population decline and found that they could be locally extinct in many parts of the United States by 2020.
The loss of all these bats would be bad for us, not just them, because they like to dine on pesky insects. So far, researchers have little idea how to cure diseased bats or stop the blight from spreading. The U.S. Forest Service last month proposed to close off abandoned mines in several states, hoping to protect the bats who live in them from the disease. For more about the bats, check out Ed Yong’s Not Exactly Rocket Science.
80beats: Frog Species Are Hopping Into Extinction Before They’re Even Discovered
80beats: Bats Are Dying from White Nose Mold, But Researchers Aren’t Sure Why
80beats: With Chirps and Trills, Bats Sing Love’s Sweet Song
Not Exactly Rocket Science: Pocket Science – lessons from spongy genomes, and a deadly bat-killing disease
Image: Al Hicks, NY DEC