In caves where 200 to 300 thousand bats used to hibernate, scientists like Scott Darling have found that this year there are only hundreds. (Photo courtesy of the US Fish and Wildlife Service)
Scientists are racing to find a way to fight-off a fungus that’s killing bats. More than a million bats have died so far. Scientists believe entire hibernating bat species could be wiped out within two decades. Laura Iiyama reports the cause might have come from overseas:
Transcript
Scientists are racing to find a way to fight-off a fungus that’s killing bats. More than a million bats have died so far. Scientists believe entire hibernating bat species could be wiped out within two decades. Laura Iiyama reports the cause might have come from overseas:
Biologist Scott Darling knew something was wrong in a recent winter when he got several calls at his Fish and Wildlife office in Vermont. People told him about hundreds of bats flying in the air and dying in the snow. During winter, the furry mammals should be hibernating.
He went to Aeolus cave. It’s where the bats in the area should be crowded together on the walls and ceiling.
“Aeolus cave became a morgue. Bats freezing to death in clusters just outside the cave entrance. Most of the bats flew out of the cave onto the landscape to certain death.”
Where 200 to 300 thousand bats had hibernated just four years ago, this year there are just a couple hundred.
The dead bats had white nose syndrome.
The white powdery fungus was first noticed on bats in New York State in 2006. It’s spread into Ontario, Canada and as far south as Tennessee.
The fungus is not directly killing the bats.
Thomas Kunz is a professor at Boston University. He suspects the fungus keeps waking-up the hibernating bats.
“It may be simply the irritation from the fungus that is causing, if you have athlete’s feet, it itches.”
Instead of hibernating, surviving on their fat reserves, the bats keep waking-up. They burn off the fat. They get too thin. And they die.
Word spread about the fungus.
Thomas Kunz says some scientists recalled seeing a white fungus on bats elsewhere:
“Bat biologists in Europe have observed and reported that there are bats that do have the fungus although it doesn’t seem to be killing them.”
Scientists think someone visited a cave in Europe. Spores from the fungus got on clothing or shoes. Then that person wore the same shoes or clothing in a cave in the U.S. The spores were picked-up by the bats.
The bats huddle together in hibernation, easily spreading the fungus.
Often 90 percent of the bats are killed-off after the first appearance of the fungus. And Kunz says that may have been what happened to bats in Europe because we don’t find as many bats in European caves as there have been in North American caves:
“Now it’s very possible that in historic times there were large numbers of hibernating bats in Europe and these are the leftovers, these were the survivors that may be resistant to the fungus.”
So the arrival of the fungus may mean US bat species will permanently drop in numbers, like the bats in Europe.
David Blehert (blee-hurt) of the US Geological Survey says if that’s the case, it will be a dramatic change in life in caves in America and Canada.
“Whereas we have hibernation caves with 100 thousand, 300 thousand and even commonly lower ten thousand but those are rather common sites where we’ve seen the fungus decimate up to 95 percent and greater to the animals in the cave. Many of the European hibernation sites have between one and thirty animals.”
There’s no treatment for white nose syndrome. And even if a cure is found, it will be a very long time –centuries– before the bats recover. Bats reproduce slowly. The females have only one pup, one baby bat, per year. And there are over a million bats dead so far.
For The Environment Report, I’m Laura Iiyama.
