A researcher using an unusual "pooper scooper" sampling method has discovered that there are at least two distinctive breeding groups of bison at Yellowstone National Park. The scientist's findings are important because many bison that wander from Yellowstone onto private land are culled or destroyed. Scientists say that could impact the balance of the herd if bison from one breeding group are being culled out more than members of another breeding group are.

Graduate student Flo Gardipee, who studies fish and wildlife biology at The University of Montana - describes herself as "a professional pooper scooper."

Gardipee explained that using feces from a bison to study its DNA is less invasive than other methods of collecting DNA. But the feces must be fresh when it is collected to obtain usable DNA.

So she and other researchers follow bison around Yellowstone and Grand Teton national parks.

"When you see that tail up and the feces dropping, you are like, 'yes!'" Gardipee said in a statement. "I totally enjoy the humor of it."

"We don't have to round them up, rough them up or manhandle them in any way," she added. "We can just go out there and kind of be amongst them."

She said that nationwide there are about a dozen known lines of bison lineage. Bison lineage is traced maternally and so far they have found two distinct breeding groups in Yellowstone.