Wood Bison Calves Born in Wild for First Time in a Century

A mother wood bison and her calf at the Alaska Wildlife Conservation Center. As of early July, 15 calves have been born in the wild. Alaska Wildlife Conservation Center/Doug Lindstrand

Wood bison, the largest animals in North America, were nearly wiped out by hunting in the late 19th and early 20th century. After an isolated herd was discovered in Alberta in 1957, wood bison have been successfully reintroduced to several locations in Canada and now number around 11,000 adults.

This past spring and early summer, a small population—130 of the animals—was reintroduced to the wilds of southwestern Alaska, near the town of Shageluk. A number of the females were pregnant, and now at least 15 mother bison have given birth to calves, according to the Alaska Wildlife Conservation Center and the state's Department of Fish and Game, which collaborated on the reintroduction effort. This is the first time in a century that newborn wood bison have roamed the American wilderness.

Already, two adult bison have been sighted 80 miles from their point of reintroduction, showing that they are healthy and eager to explore their vast new habitat. Wood bison (Bison bison athabascae) are northern cousins to plains bison (Bison bison bison), the species also known as buffalo and probably more familiar to U.S. residents. Wood bison are bigger—one of the bulls just released weighs 2,400 pounds, whereas plains buffalo max out at a ton.

An aerial shot of wood bison and their calves in the wilds of southwestern Alaska. If you look closely, you can see some calves next to their mothers in the image's left-center area. Alaska Dept. of Fish & Game

These animals live off grazing on grass, an ecological niche that hasn't been filled in the area since the beast disappeared from Alaska a century ago. This loss decreases biodiversity and left less food for predators and Native Americans, which once hunted the animals for their meat and thick hides.

By the end of July, mating season will begin, and the 30 adult males will vie for dominance as they try to win over mates. A small herd of the animals remains in the wildlife center outside Anchorage, where the beasts were initially bred, and can be seen by the public.

A wood bison calf. Alaska Wildlife Conservation Center/Doug Lindstrand