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| There are hopes this is an early sign that bats can adapt to a disease that has spread to 19 states and Canada. |
Figures released by the state Department of Environmental Conservation showed notable increases in the number of little brown bats in three out of five upstate New York hibernation caves where scientists first noticed white nose decimating winter bat populations six years ago. The largest cave saw an increase from 1,496 little browns last year to 2,402 this winter.
There are hopes this is an early sign that bats can adapt to a disease that has spread to 19 states and Canada. But scientists caution it's far too early to tell if it is the start of a trend or a statistical blip.
“While we remain cautiously optimistic of encouraging trends for some species seen more recently, it will likely take several years before we fully know how to interpret this,” said Kathleen Moser, the agency's assistant commissioner of natural resources.
White-nose, named for the sugary smudges found on affected bats' snouts, prompts bats to wake from their winter hibernation and die when they fly into the winter landscape in a futile search for food. First detected in 2006, the fungal infection has killed more than 5.7 million bats as it spread from the Northeast. In recent weeks, the disease has shown up in Alabama and Missouri, marking its advance west of the Mississippi River.
Scientists fear the disease could push some species to extinction and dramatically reduce the population of an animal that farmers depend on for natural pest control.
The survey found that statewide losses of little browns, the most common bat species in New York before white-nose, remain at about 90 percent.
New York state bat biologist Carl Herzog said that while counts were up in the three caves west of Albany for little browns, bat-counters could have missed some in previous surveys and new bats coming to hibernate in the caves are a contributing factor.
But the possibility that bat populations could adapt to the fungus has long been the hope of scientists.
“That's what the perfect scenario would be - that the area that was first hit would be the first to recover because they would have had more time to adapt to the pathogen,” said Beth Buckles, an anatomic pathologist at the College of Veterinary Medicine at Cornell University.
Buckle, who is not involved in this project, said while she's hopeful, she needs to see more data over more years.
In an effort to track the long-term effect of white-nose, Herzog and a team of researchers caught bats outside one early-hit hibernation cave on a recent moonlit night. Bats that flew out for an insect snack hit filament lines and fell into a bag where they were snatched up to be swabbed and examined.
As bats chirped in protest, their wings were stretched flat on an ultraviolet light table about twice the size of a smartphone screen. When the purple light shined through the translucent wing, infected spots that can't be seen with the naked eye became fluorescent orange.
The infection patterns were photographed and will be compared with those of bats that succumbed to the disease years ago and with newly infected bats in Pennsylvania. They will also be compared with bats in the Czech Republic. Scientists recently confirmed that white-nose fungus hitchhiked from Europe, possibly on the boots or clothes of a well-travelled caver.
Based on observations so far, Herzog said bats from the long-exposed cave are dealing with the disease better.
But he said despite some good news from early-hit caves, there are still more questions than answers.
“This is not a widespread phenomenon,” Herzog said. “Hopefully it will be.”
Source: IOL