Salem College Professor Helping to Save Local Bat Population
From superheroes to vampires, bats have become icons in our popular culture. But look to the sky at twilight and you’ll see the real deal; skilled and nimble predators flying jagged paths, hunting for insects with their echolocating sonar.
They are their own group of mammals, the Chiroptera,
That’s Traci Porter, Associate Professor of Biology at Salem College in Winston-Salem.
Basically their hands are their wings, so “Chiro” meaning “hand,” like a chiropractor. There are over a thousand different species of bats in the world, and it's estimated that one out of every five mammals is a bat.
This mammal has evolved great skills and diversity, occupying most of the earth’s habitats. Though their fossil record is sketchy at best, they are believed to share a common ancestor with primates, whales and rodents because these are all placental animals, meaning that they give live birth. It’s also likely they’ve been around long enough to have flown around the heads of the dinosaurs. In the winter of 2006-2007, a new disease was documented among several species of bats, and it has now spread over the eastern United States and into Canada. To date it is estimated to have killed more than five and a half million bats.
White-nose syndrome is a fungal disease. It is a fungus that likes to feed on their skin. It makes this powdery, cottony fluff on their noses. But also can get on their ears, and on their tails, and eats away at their skin. It really likes the colder temperatures that their body drops down to while they’re hibernating. And it causes them to wake up more often. It causes higher carbon dioxide levels in their blood, which also causes them to wake up more often. They tend to use up their energy and then they starve to death because they’re using their energy at a time when there are no bugs available for them to eat. Bats mostly pass it to each other in the caves, so that, once it reaches one cave, it quickly spreads.
One way any species can evolve is by naturally selecting for immunity to a disease. Something like that may be happening here.
We think it was brought over from Europe because they do have this in the European caves. But, they seem to have some sort of resistance to it, as if it has already gone through and cleaned out anybody who didn’t have resistance, and then left those who have a resistance to the fungus.
The disease is still infecting bats, and a definite cure has not yet been found. But there is one promising solution being tested right now.
You can’t just use a normal fungicide in a cave because there are a whole lot of fungus that makes the cave ecosystem work. This team, led by Chris Cornelison from Georgia State University has found a bacterium that emits airborne chemicals that inhibit the growth of this white-nose syndrome-causing fungus. This is a normal bacterium that lives in soils everywhere. They still need to test it to find out whether it is something that is going to affect negatively other fungi or organisms in the caves.
But there may be something else going on here, which is another area of Dr. Porter’s research, having to do do with how one species adapts to the presence or absence of another species occupying the same habitat.
So in particular, these bats that are called Little Brown Bats are ones that are most affected by it, and we’re seeing a decline in those species. But I’m wondering too, is there an increase in other species that are not affected by white-nose syndrome. Say, Red Bats for example, and wondering if, when freed from competition for the same sorts of insects, that they might actually have a bit of a boost in their population. You would think other bats that are foraging in the same areas on mostly the same insects would have a real banquet. And so that’s my hypothesis is that we’re going to see or may be seeing a surge in some of these bats. Bats in North Carolina are extremely important for eating pest insects that are attacking our crops, that are attacking forest species, plant species, so having the balance with bats eating these insects, moths, beetles and mosquitos and so on, is so very important, and it’s been estimated that bats’ contribution to agriculture in terms of pest control is worth at least 3.7 billion dollars.