Study Examines Genetics Of Bison In Theodore Roosevelt Park

WATFORD CITY, N.D. – Research underway at Theodore Roosevelt National Park aims to help scientists better understand bison in order to conserve the species.

Researchers recently collected tissue samples from 100 bison in the north and south units of the park that will be compared with bones and fossils collected in North Dakota, said Bill Whitworth, chief of resource management for the park.

The goal of the project is to better understand the genetic diversity of the American bison, officially named the national mammal earlier this year.

“Genetic diversity allows animals to adapt to change,” Whitworth said. “The more diverse they are, the more likely they are to adapt to changing circumstances.”

A bison rests in the prairie grass of the North Unit of Theodore Roosevelt National Park recently. Photos by Eric Hylden/Grand Forks Herald
A bison rests in the prairie grass of the North Unit of Theodore Roosevelt National Park recently. Photos by Eric Hylden/Grand Forks Herald

Theodore Roosevelt National Park reintroduced 17 bison to the South Unit in 1956 from the Fort Niobrara National Wildlife Refuge. Twenty bison were transferred to the North Unit in 1962.

Today the herds average between 250 and 500 at the South Unit and between 150 and 300 at the North Unit.

The North Unit’s population is approaching the upper limit, so a bison roundup is planned for this fall to remove 90 to 100 animals, Whitworth said. The size of the herd is managed conservatively to make sure bison and other wildlife in the park have enough forage, even in dry years.

“Whether we get a lot of rain or no rain, we can support the bison that we have,” Whitworth said.

The research will establish baseline information about bison genetics that can help the National Park Service better manage bison populations.

Some bison populations were cross bred with cattle, so one question that comes up is how “pure” the bison are, Whitworth said. The research will also help address concerns about inbreeding, Whitworth said.

Field work is expected to be completed this year, he said.