Six American Bison calves have been born at WCS’s (Wildlife Conservation Society) Bronx Zoo, and four of them are now on exhibit on the Zoo’s ‘Bison Range’.

The calves were born to a herd of seven females and one male that arrived at the Bronx Zoo from Ft. Peck, Montana in November 2016.

The herd was a historic gift from the Assiniboine and Sioux tribes. The Fort Peck Bison are from the Yellowstone National Park bloodline and are among the few pure Bison remaining. The vast majority of present-day Bison, or Buffalo, have trace amounts of domestic cattle genes, a reflection of past interbreeding efforts when western ranchers tried to create a hardier breed of cattle. (More information about the historic gift and transfer can be found at the WCS Newsroom: http://bit.ly/2qTVHvF ).

The female Bison were pregnant when they arrived at the Zoo, and the calves were born in late April. “These calves will bolster our efforts to expand our breeding program of pure Bison,” said Dr. Pat Thomas, WCS Vice President/General Curator and Associate Director of the Bronx Zoo. “They will eventually be bred with other pure Bison to create new breeding herds in other AZA-accredited zoos, and to provide animals for restoration programs in the American West.”

Photo Credits: WCS/ Julie Larsen Maher

The Bronx Zoo has a long history of facilitating Bison conservation projects in the western U.S., and the birth of these calves provides a welcome boost to the Zoo’s ongoing efforts to establish a herd of pure Bison.

For more than five years, the Bronx Zoo has worked on developing a herd of pure bloodline through embryo transfer. The Bison from Ft. Peck will supplement those efforts. The bull, currently on exhibit with the females and calves, was the first American Bison born as a result of embryo transfer in 2012. (More information about the Bronx Zoo’s efforts to breed bison through embryo transfer can be found on the WCS Newsroom: http://bit.ly/2q6kji7 ).

The American Bison (Bison bison), also commonly known as the “American Buffalo” or simply “Buffalo”, is a species that once roamed the grasslands of North America in massive herds. They became nearly extinct by a combination of commercial hunting and slaughter in the 19th century and introduction of bovine diseases from domestic cattle.

However, the Bison is now an American conservation success story. In the early 1900’s, the species was on the verge of extinction: numbering fewer than 1,100 individuals, after roaming North America in the tens of millions only a century earlier. In 1907 and 1913, the Bronx Zoo sent herds of Bronx-bred Bison out west to re-establish the species in its native habitat.