Bronx, NY – May 13, 2022 – Three male and three female Bronx Zoo-born American bison (commonly called buffalo) have been transferred to the Osage Nation in Pawhuska, Oklahoma. This week, those bison joined the nearly 200 bison that make up the resident Osage herd on their 43,000-acre ranch and will bolster the genetic diversity in the Osage herd.

This move is a significant step in a new partnership between the Bronx Zoo and the Osage Nation. It is the culmination of years of work on an important conservation program that had its beginnings more than a century ago when the American bison faced extinction and the U.S. bison population numbered fewer than 1,000 animals.

Bronx Zoo officials were on site with Osage Nation leadership at the successful culmination of the project when the Bronx Zoo bison were introduced to the resident herd on the Osage Reservation.

“The transfer of Bronx Zoo bison to the Osage Nation is a win-win,” said Dr. Patrick Thomas, the Bronx Zoo’s Associate Director and General Curator, who initiated and oversaw the zoo’s role in the project. “The Osage again have a species of cultural importance grazing on their ancestral land; the zoo’s bison get to play an integral role in a significant conservation program; and the tallgrass prairie ecosystem benefits by having bison on it, thereby shaping the composition of the vegetation and animal communities.”

Said Chief Geoffrey Standing Bear of the Osage Nation: “The return of the bison holds great significance to Osage people. Bison are not only a mark of our past; they are a symbol of our future. With the great success of our surface reservation growth through land purchases, we now have a home for bison to continue their resurgence. On behalf of the Osage Nation, I would like to express gratitude to the Bronx Zoo for its conservation efforts and programs that contribute to the growth and diversification of our herd.”

Importance of Bison to the Osage Nation

The people of the Osage Nation have an historical and cultural relationship with bison, and bison remain an important element in Osage life. Historically, Osages had two buffalo hunts – summer and fall – which were deeply rooted in the Osage way of life. Because so much of their food, clothing and tools centered around bison, elaborate preparations would be made for the hunts. While bison hunts no longer occur, a growing and healthy bison herd on the Osage reservation is a symbolic representation of a thriving Osage Nation.

Bronx Zoo Breeding

For more than a decade, the Bronx Zoo has been working to establish a bison herd of conservation value with the goal of re-establishing bison herds to areas they once occupied in the American west.

The Bronx Zoo’s current bison program began in 2012 as a collaborative embryo transfer (ET) project with Colorado State University (CSU). Pure bison embryos were collected from female bison at CSU and implanted in the zoo’s surrogate bison cows. Although this program saw limited success because ET techniques in bison are not yet well developed, the first plains bison produced by embryo transfer occurred at the Bronx Zoo as a result of this initiative.

The next significant move in the Bronx Zoo’s bison program came in 2016 when the zoo received a gift of seven female and one male bison from the Sioux and Assiniboine tribes in Ft. Peck, Montana. These animals were of the important Yellowstone bloodline, one of the few remaining herds of pure bison. Upon arrival at the Bronx Zoo, they were selectively bred to maximize genetic diversity in the population. By 2022 the Bronx Zoo’s herd had grown to 37 animals and the goal of reintroduction was within reach.

Bronx Zoo/WCS Historical Conservation

The partnership between the Bronx Zoo and the Osage Nation is historical. It represents an ongoing legacy project for the Bronx Zoo, and it is the continuation of one of the most successful conservation programs in U.S. history – the recovery of the American bison.

Bison populations in North America once numbered in the tens-of-millions. Over much of the 1800s they were relentlessly hunted, and in less than 100 years, the species was driven to the brink of extinction, with fewer than 1000 animals remaining in the wild and in captive herds. The decline was largely due to commercial hunting and slaughter, which was facilitated by expansion of the railroad into the West, and the advent of more accurate and efficient rifles.

In 1895, the New York Zoological Society (now the Wildlife Conservation Society) which created and still operates the Bronx Zoo, was established. The first director of the Bronx Zoo, William Hornaday, was an avid conservationist and one of the founding members of the American Bison Society (ABS) in 1905, with the stated goal of saving the bison from extinction. 

Hornaday acquired bison from private ranchers for the Bronx Zoo and began breeding the species with the intent of reintroducing them into the wild.

In 1907 the ABS sent 15 Bronx Zoo bison to the Wichita Reserve Bison Refuge in Oklahoma. In 1913, the Society sent another 14 Bronx Zoo bison to Wind Cave National Game Preserve in South Dakota. This reintroduction work, combined with efforts by the Salish and Kootenai tribes, was so successful that by 1935 the ABS held its last meeting and declared the bison no longer in danger of extinction. 

Today, there are about 500,000 bison in the wild and on ranches across North America, but most of these bison carry trace amounts of domestic cattle genes from a time when bison numbers were at their lowest and ranchers attempted to breed bison with cattle in order to create larger, heartier beef cattle.  Only about 11,000 of the 500,000 animals alive today are thought to be genetically pure bison with no evidence of cattle genes. The majority of these are bison that originated from Yellowstone National Park. 

The Wichita Reserve Bison Refuge in Oklahoma still exists today. Many of the bison in the conservation herd managed by the Osage Nation were sourced from the reserve and could possibly be distantly related to the bison originally moved from the Bronx Zoo in 1907.

Media Photo/Video:

Video – Osage herd with aerials

Credit © Bronx Zoo/WCS


Video – Transfer from Bronx Zoo; arrival in Oklahoma

Credit © Bronx Zoo/WCS


High Resolution Photos – Bison on Osage Nation Ranch

Credit: Julie Larsen Maher © Bronx Zoo/WCS


Historic Photos – Bison transfer from Bronx Zoo to Oklahoma (1907)

Credit © Bronx Zoo/WCS