Bison Bellows: The Kaibab Plateau Bison Herd of Grand Canyon National Park

In winter, small groups of bison wander along the park's North Rim. NPS photo/J. H. Thompson.

Think of the Grand Canyon and you picture mile-deep canyons, the winding Colorado River and its archeological wonders. The park has 277 miles of river, 4,300 archeological resources and the 21-mile "Rim to Rim" trail. What few people picture is its herd of roughly 500 free-ranging wild bison, living on the Kaibab Plateau, including the park's North Rim and the lands next to it.

Where they came from

Today's herd descends from 86 bison that Charles "Buffalo" Jones brought to Arizona from Kansas in 1906, some of them captured wild in Texas. Jones was known for working to save bison from extinction, and like other ranchers who led early bison conservation, he tried crossing bison with cattle.

With little knowledge of genetics, he mostly failed: a bison bull crossed with a domestic cow produces fertile female offspring but no fertile males, a sign that a true hybrid of the two species is not possible. Jones realised this after a few years, sold some of the animals, and largely abandoned the remaining 15–20 until they were sold to Arizona in 1928.

Are they "pure" bison?

Most of the park's bison carry some cattle mitochondrial DNA, the DNA inherited from the mother, although nobody has deliberately crossed them with cattle in over 100 years. Mitochondrial DNA may affect how cells work, but most inherited traits are carried by chromosomal DNA, which holds most of an animal's DNA, and the small traces of cattle genes probably make little difference to how the herd breeds or looks. They look and behave like wild bison conserved elsewhere in North America.

The failed crossbreeding experiments of the early 20th century were never repeated, but they still colour public ideas about "pure" bison. Studies show that only a few conservation herds today carry no trace of cattle genes, and many that do are valuable to the species' conservation. The Kaibab herd's genetics could be improved, but that does not stop it being an ecologically meaningful wild herd that contributes to bison conservation. Managers today are working together on the species' long-term survival.

Update, March 2023

The National Park Service will reduce the size of the Kaibab Plateau herd by 2025, through capture and relocation and through lethal culling. The environmental assessment, finding of no significant impact and other documents are on the NPS Planning, Environment and Public Comment site; operational details, including volunteer opportunities, are announced in the park's news releases.

Did you know?

Some tribal stories of the region mention bison in northern Arizona. In one historical Hopi oral story, members of the Ute Tribe came to visit their Hopi relatives and brought a herd of bison as gifts.

More

• Grand Canyon bison management
• Bison at Grand Canyon: Kaibab Plateau herd information
• Bison effects research and monitoring
• Wildlife viewing and safety tips
• More Bison Bellows, the weekly series from the NPS Biological Resources Division in Fort Collins, Colorado, about meeting the herds, meeting the people and telling the story of bison.

Sources

• National Park Service, "Bison Bellows: Grand Canyon National Park." https://www.nps.gov/articles/bison-bellows-4-21-16.htm
• Words on this page from people and organisations outside the federal government are paraphrased; rewritten in hubnx's own words.