A deadly fungus that has killed about a million bats on the east coast, known as white nose syndrome, has local biologists worried because it’s spreading westward.
They’re uncertain, however, whether the fungus, which relies on cold temperatures, will mutate into something that can survive warmer Sacramento-like winters, explained Winston Lancaster, an associate professor of biological sciences at Sacramento State University who has been studying bats since the 1980s.
“What’s the greater likelihood is that it will be different. We just don’t know what to expect,” Lancaster said. “So there is good reason to believe that in a drier climate and in an open sort of roost, like we have in bridges here, it may not ever be established.”
But biological organisms adapt. So the question, Lancaster said, is whether the fungus will still have the same pathogenic effect on these animals. “Maybe, maybe not,” he said.
Found in one cave in New York, white nose syndrome has resulted in the death of 95 percent of the little brown bat (Myotis lucifugus) population and has killed some bats from other species as well, Lancaster said.
He added that it’s thought that the fungus was brought to the United States in 2006 from Europe by the shoes or clothes of tourists. More recently, scientists have seen it move down the Appalachian Mountains and west to Oklahoma.
Unfortunately, not much can be done to stop white nose syndrome from spreading, but here on the other side of the continent, scientists can see the storm coming, Lancaster said.
“We have time to react.… We need to make sure we have our methods of handling animals such that we won’t be the agent of dispersal,” he said.
What’s likely to happen is that someone will inadvertently spread this on their shoes or on their clothing, he said, so officials have been trying to restrict access to infected areas. “But it becomes an extremely difficult thing to do – to completely close caves. It’s very expensive and it’s very difficult to accomplish.”
Meanwhile, the U.S. Fish & Wildlife Service has called for a moratorium on caving activities in the affected areas and recommends that any clothing or equipment used in such areas be decontaminated after each use.
So when Lancaster takes graduate students in a few weeks to the Sutter Buttes to catch bats, they have to follow the new protocol.
“We never did this before,” Lancaster said. “We only started this last year. All these protocols are meant to change our behavior so that, if I catch a bat that has this fungus on it … I’m not going to inadvertently transfer that fungus to a bat that lives in a totally different place.”
Lancaster explained that the fungus has been found around bats’ wings, mouths and ears when they are hibernating in caves during winter and seems to disrupt their hibernation patterns.
“It is known they do wake up and it’s not sure why they are waking up,” he said. “Are they looking for water? Are they trying to look for food?” Lancaster continued, noting that the bats don’t have enough energy to go through the winter if they’re waking up from hibernation early.
When animals go into hibernation, Lancaster explained, they let their bodies get cold so they can save energy, but after a few days, they need to take a few hours to warm up. That spike in temperature accounts for 90 percent of their energy use, he said. But if the animals are waking up and staying awake longer than those spikes, they’re in danger of running out of energy before the winter is over.
In warmer Sacramento, bats don’t hibernate but go down into a torpor, or deep sleep, after their daily roost to allow their body temperatures to drop.
“These are tiny animals with fast metabolisms, so if they had to keep their metabolism up to full speed all day long, they would have to eat more,” he said. “(Here) they go into mini hibernations every day unless temperatures stay down below 50 degrees at days at a time.”
It’s thought that the Mexican free tail, a common local bat species, may be an asymptomatic carrier, meaning it might not be affected by the fungus, but tens to be a migratory animal. So there’s the possibility it could carry spores from one roost to another, Lancaster said.
Many farmers are in favor of protecting bats because they not only eat the insects that damage their crops but unlike chemical pesticides, they turn insects into fertilizer. On the Yolo Causeway, hundreds of thousands of Mexican free tail bats work in farmers’ fields.
According to an article in Science Magazine titled “Economic Importance of Bats in Agriculture” the loss of bats due to white nose syndrome and wind turbines states estimate a loss of $3.7 billion per year in North America.
To learn more about white nose syndrome, visit the U.S. Fish and Wildlife Service website at http://www.fws.gov/whitenosesyndrome/