Why Little Brown Bats Are Sick
The mystery of why millions of bats in North America have been dying over the past several years may be solved. White nose syndrome, as the disease is known, appears to be caused by a fungus from Europe, and was probably brought in unwittingly, perhaps by a tourist.
More than 5.7 million bats have died since 2006 when white nose syndrome was first detected in a cave in upstate New York. It is devastating not only to the bats but to flowering plants, including our own food crops that depend on them for pollination. And since bats consume enormous numbers of flying insects at night, their disappearance could seriously upset the balance of nature and result in swarms of insects creating havoc on plant life.
A new study shows that the cause of the sickness is not native to North America.
A team of researchers from the U.S. and Canada conducted on experiments on different groups of bats they’d collected to establish the cause of the disease. According to the Canadian Press:
[They] set out to determine whether the fungus behind white nose syndrome was native to this continent or invaded from abroad. To do this, they collected 54 little brown bats from an uninfected cave in Manitoba.
The bats were divided into three groups: One group was infected with spores collected from Europe; another group was sickened with spores from North America. A third group was not infected. Researchers used infrared cameras to monitor the bats’ behavior and disease progression over several months.
Both infected groups developed symptoms, including the telltale trace of white powder on the nose that gives the disease its name and scarring on the wings. Compared with uninfected bats, infected bats were roused more often from hibernation. This depletes their fat reserves and ultimately leads to death.
“As much as it breaks my heart, this tells us that people inadvertently brought it from one place to another by not cleaning their boots or pants,” Brock Fenton, a bat biologist at Western University in Ontario told Discovery News. “Before, you could at least say here’s a calamity but it was not caused by humans. Now, I don’t think you can believe that anymore.”
Theoretically, understanding how the disease works and spreads could lead to interventions that would slow or stop it. But there are still many unanswered questions, and a cure remains elusive.
“I don’t think this paper gives us any better handle on solving the problem than we had before, which was no handle at all,” Fenton said. “Right now, the outlook is really bleak.”
The complete findings were reported on Monday in the Proceedings of the National Academy of Sciences.
(Note: this website does not condone experimentation on any animals.)