Warmer-than-normal temperatures may be linked to the deaths of thousands of local bats, state wildlife pathologist Ward Stone said Tuesday.
Federal and state officials last week asked cavers to stay out of caves known to house bats while an investigation into the die-off ensued.
Between 8,000 and 11,000 bats were found dead where they hibernate near Albany last year, and wildlife officials last month found bats dead or dying in a Schoharie County cave and in a cave in Vermont.
A white fungus, called fusarium, surrounded the noses of some of the bats, both living and dead, and officials feared the fungus might have played some role in the deaths.
Stone on Tuesday said samples of the fungus were sent to a federal lab, but for the most part, the fungus does not appear to be killing the bats.
Stone said he has received calls about bats flying around this week when they would typically be hibernating.
The unseasonable temperatures might be waking them up, he said.
“The bats are starving. They have burned up their energy supplies and they are ready to go get something to eat, I think. But there’s little to nothing available because it’s winter.”
Adding to the bats’ plight is a dwindling food staple. One of their primary food sources, moths, are declining in numbers in the Capital Region, Stone said.
State entomologist Timothy McCabe, curator of entomology at the New York State Museum, said he’s noticed a reduction in some bug species favored by bats.
“I think one of the primary, if not the main, source of food for bats is moths. Since about 1986, I’ve seen a marked decline in moths in our part of New York state,” McCabe said.
McCabe said a colleague who works in New Jersey has not seen a similar trend, nor has he seen a decline of moths in the Adirondacks.
“I don’t know how widespread the phenomena is, but there’s been a dramatic reduction in the Capital District area,” McCabe said.
McCabe said he’s seen theories written in scientific journals that point to parasites in caterpillars causing reduction in their numbers.
Light pollution, which McCabe attributes to increased streetlights and other lights as residential and other development has steadily grown in the Capital Region, could also be throwing off the moths’ rhythm, making them think it’s daytime instead of nighttime, when they’re usually out roaming.
Meanwhile, Stone said, studies are ongoing to determine whether the fungus or any other contaminants are contributing to the death of the bats.
He said it is possible that factors such as changes in cave environments, also due to weather, could be promoting the growth of the white fungus.
“Strange weather has occurred in the last two years … it weakened [the bats] and put them into a starvation state. That has created this situation,” Stone theorized.
Stone said more study, which is sensitive because of the possibility that bats can carry rabies, needs to be done before a definitive answer can be established.
“We have to make sure we have everything right, plus look at the virus, the bacteria and toxic substances and think about rabies continuously,” Stone said.
State Department of Environmental Conservation spokesman Yancey Roy said Tuesday he had not received any update on the investigation into the bat deaths.
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