Old Animal Specimens May Hold The Key To New Discoveries
Friday, April 13, 2018
You find all kinds of things in drawers when you're getting ready to move. Expired credit cards. Single socks. Concert tickets. Chargers from old phones. Two-foot-long dead squirrels.
Well, maybe not the squirrels - unless you're a scientist moving to a new lab. That's what happened in the Biology Department at Mercer University in Macon, Ga.
Last year, the department moved into a brand new building with state-of-the-art genetics labs, technology in the lecture halls - the works. Biologist Craig Byron was helping pack up when he came across a forgotten metal cabinet. It was big, blue, and stuffed with animal specimens, mostly collected in the 1950s.
The day before the building move, Byron poked through the contents: animals trapped, killed, and preserved decades ago in the name of science.
He compared two skulls in a group of skeletal remains. One, he said, was from a possum. "You can tell because it's got a tiny little brain compared to a similarly sized...probably a raccoon or something here."
And then there were the animals preserved flat to fit in drawers, with their arms out Superman-style. Red foxes, bats, bobcats.
Eventually Byron got to a layer of fox squirrels. One bore a tag with the date and location of its collection: Bibb County, November 20, 1958.
Byron paused. "I've never seen a fox squirrel in Bibb County," he said. That's the Georgia county where Macon - and Mercer University - are located.
At twice the size of gray squirrels, fox squirrels need special habitat: mature stands of longleaf pine forest. There's none of that in Bibb County today, but this squirrel told us there once was - at least on November 20, 1958.
As cool as that insight was, the collection couldn't stay at Mercer. There wasn't space for it in the new building. The birds in the cabinet would go to Louisiana State University. And the mammals?
"Somebody in D.C. wants them," Craig Byron said.
That somebody is Suzanne Peurach at the Biological Survey Unit, part of the U.S. Geological Survey. It's the largest animal research collection in the world, 600,000 specimens total, and it's housed at the Smithsonian. Some are preserved flat like the Byron's fox squirrel. Some are stored in jars of ethanol - BIG jars, big enough to fit zebras and gorillas and pygmy hippos, according to Peurach. She curates the 300,000-plus North American specimens.
Researchers ask to look at the collection for all kinds of reasons. Some want to make inferences about how the ecosystem has changed, as in the case of the Bibb County fox squirrel. Others use isotope analysis of the preserved animals to provide a window into how a species's diet changes over time with changes in their environment. Some scientists even collect the tiny creatures that lived on the preserved specimens, to help further our understanding of microbiomes.
"The point of these collections is we don't know what they're going to be used for," Peurach said.
She offered an example from her college days at the University of New Mexico in the 1990s. She and her mentor Terry Yates got a message to come back to the lab from their field work, as soon as possible.
"People were dying from a mystery illness and they thought it might be related to mammals," Peurach remembered. This was in the Four Corners area, where Arizona, Utah, Colorado, and New Mexico meet.
Investigators from the Centers for Disease Control came to look for clues in Yates' collection of preserved deer mice - which they knew can carry deadly hantavirus. When they looked at tissue from years and years worth of mice, researchers saw hantavirus outbreaks occurring at regular intervals. That information about the cyclical outbreaks would help scientists predict the next one.
"And then all of a sudden it was like a lightning bolt hit me," said Peurach.
She realized: those mice in drawers? They weren't just for arcane lab research. They could save lives.
Federal budget talk heated up after we spoke with Suzanne Peurach. Some science programs were cut in the new federal spending bill, but the six-person Biological Survey Unit isn't even named in the legislation; it isn't clearly cut nor funded. So while the Unit waits for answers, Peurach is holding off on taking more specimens.
That's why the animals biologist Craig Byron found at Mercer University have only moved across the street from where he found them. Today they are in the basement of the brand new science building, packed into cardboard shipping boxes and waiting on a pallet.
"But they're still just kind of in limbo," Byron said.
We can't know yet what questions the Mercer University bats, muskrats, and fox squirrels may be able to answer someday. For now, they're still looking for a good home.
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