Student Research project: Parasites prevalent in bulls and juvenile bison

While interning with The Nature Conservancy in South Dakota in August 2015, Lisa Zoromski, a University of Wisconsin – Stevens Point senior, found that bulls and juveniles in the free-ranging bison (Bison bison) population the group oversaw carried more parasites than cows and calves. For this work, Zoromski took home an honorable mention in the student poster session at the TWS Annual Conference in Raleigh, N.C., last October.

Although she was helping The Nature Conservancy with behavioral research at the 3,000-acre Samuel H. Ordway Jr. Memorial Preserve, Zoromski wanted to investigate the kinds and amounts of parasites the bison bore because no one had studied parasites in that population before. She climbed into a pickup truck, drove into the herd, observed the animals defecating, collected fresh fecal samples and recorded which of the 300 identified individuals each sample came from.

By analyzing the scat, Zoromski discovered that over 20 percent contained roundworms, which, at high concentrations, can cause diarrhea and weight loss. Overall, her data showed that the worms were more common in feces from males and 1- to 3-year-old bison and has helped managers at The Nature Conservancy.

“When they’re deworming them now, they’re focusing on the younger bison and bulls,” Zoromski said, noting that the managers hadn’t strategized their effort until she showed them her data and increased their efficiency.

This was Zoromski’s second TWS Annual Conference and her first time participating in the poster contest, so she said she wasn’t expecting the award.

“I enjoyed the conference a lot,” she said. “It was really helpful learning from everyone, the questions they had and being able to answer them. Finding people interested in what I was studying was cool. It was a good way to meet people.”

A TWS member, Zoromski is president of her student chapter and student representative for the Wisconsin Chapter and North Central Section. A wildlife ecology, research and management major, she developed an interest in parasites through a college advisor and is now examining parasites in the eastern cottontail (Sylvilagus floridanus).