Up to now, stable hydrogen isotopes have been used mostly to track migratory birds.
"Relatively little is known about bat-to-bat interactions or how far bats travel between seasonal habitats," Sullivan explains. Earlier attempts to use hydrogen isotopes with bats stalled because most hibernating bats don't make dramatic seasonal migrations, and they have unclear molt patterns, making it difficult to connect their hair to a given habitat, she adds.
In their latest study, Sullivan, Bump and colleagues were able to estimate with 95 percent certainty the summer origins of the tens of thousands of bats that hibernate in the Quincy Mine, the 23,000 bats in the Norway Mine and the estimated quarter of a million bats that call the Caledonia Mine their winter home. Using the hydrogen "fingerprints" from hair samples, they located the geographic areas from which the bats migratesome as far as 565 kilometers (351 miles) from their hibernation mine.
"This novel application of stable hydrogen isotopes can help predict which hibernation sites are likely to exchange bats," says Bump. Bat-to-bat contact is believed to be the way white-nose syndrome is spread, so understanding the bats' movements can help us know which hibernation sites are connected and how disease could potentially be transmitted among locations."
Although white-nose syndrome has not been seen among bats in the Upper Peninsula of Michigan yet, it is decimating bat populations in the northeastern US.
And why should anyone care what happens to these reclusive winged creatures that weigh less than half an ounce and average 3.4 inches long?
"First, they are amazing mammals. Second, we should care about little brown bats because they eat millions of things for which we care much less, like mosquitos," says Bump.
|Contact: Joseph Bump|
Michigan Technological University