The American bison and its gigantic ancestors

The American plain bison (Bison b. bison) with a shoulder height up to 1,9m, their large head and massive front bodies are always impressive animals and an attraction for every zoo. Even when we see only a few American plain bison, it is easy to imagine the powerful impression of the large herds, which lived in former times in the North American open grasslands. In the 17th and 18th century, the numbers of the American plain bison are estimated on 60 million animals. Due to overhunting by the European immigrants and due to diseases, which were brought in by the European farmers with their imported cattle, only 835 American plain bison were still alive in 1889.

The situation of the other North American subspecies, the Wood bison (Bison b. athabascae), which lives north of the American plain bison, was even worse. This subspecies was believed to be extinct, but in 1960 a small herd of 200 animals were found in Canada in an area, which was already founded as Wood Buffalo Park in 1915.

Because of protection and breeding programs, the status of the American plain bison is today secure and the number of Wood bison increased again to about 1.800 animals.

Two drawings of the European bison in its natural habitat (1893 b/w, 1910 colored)
(Click to view larger image).

The American bison, drawn in the beginning of 19th century (Click to view larger image).

However, bison are found not only in North America, but also in Europe, namely the European bison (Bison bonasus). The situation for the bison was in Europe not better than in North America. The two subspecies of the European bison were endangered to become extinct too. In 1927 the last European bison in the wild was shot in the Caucasus, after the Lowland bison was already extinct in the wild since 1919. Today the Caucasus bison (Bison b. caucasicus) is extinct. Due to early conservation and breeding programs of the European zoos the Lowland bison (Bison b. bonasus) survived in the zoos and in 1952 the first animals could be reintroduced to the wild again. Today, the whole stock of European bison in the wild and in the zoos goes back on only 12 animals, which survived in the European zoos. It was the Berlin zoo, which started in 1923 the first studbook for a wild animal species at all, namely for the European bison.

The European bison looks due to its slender body on the first glimpse smaller than the American bison, but in reality the European species is a bit larger (shoulder height up to 2m) than the American bison.

But all these bison species are really pigmy forms compared with their ancestors, the Steppe bison (Bison priscus) and the Long-horned bison or Giant bison (Bison latifrons).

The extinct Steppe bison was over 2m tall and its horns were more than 50cm long and their tips were 1m apart. The Steppe bison lived on steppes throughout Europe and Central Asia. During the late Pleistocene, 240.000- 220.000 years ago, it migrated via the Bering land bridge from Siberia to Alaska and inhabited then large parts of North America. The species became extinct in the late Pleistocene, about 21.000-30.000 years ago. It was replaced in Europe by the modern European Bison and in North America by the Giant bison and later on by the smaller Ancient bison (Bison antiquus), which evolved some 10.000 years ago into the modern American bison.

Skull of the Giant bison, Leiden Museum Netherlands (Click to view larger image).

The Giant bison reached a shoulder-height of 2,5m and weighed probably over 2.000kg. Its horns measured from tip to tip 213cm (!), whereas the horns of the modern American bison have only 65cm distance. The males used their long horns probably against the large carnivores and to establish dominance in comparison with other males for the right to mate. The Giant bison is probably the largest bovid, which ever lived. They were found in the Great Plains and the woodlands of North America with a preference to a warmer climate. Their fossils are found as far south as California.

Almost in the same time, when the Giant bison died out, from 18.000 years ago until 10.000 years ago, the Ancient bison became increasingly abundant in the center of North America. The species was not so gigantic as the Giant bison, but still about 20-25% larger than modern American bison. The Ancient bison has a shoulder height up to 2,2m and its horns measured from tip to tip about 1m. - About 10.000 year ago also this species died out and gave place to the modern American bison.

Giant bison in the Lost Zoo (Click to view larger image).

When we see today very large animals like the bison, it is sometimes hard to imagine that in past times their next related species or ancestors have been even much bigger. To imagine that the man already lived in that time, it must be a scenario like in some fairy tales, when kids become small like a doll and live between the normal people, who are suddenly giants, and when the whole environment suddenly is much too large to be used. To get an impression of the gigantic size of some extinct animals, which lived in former geological periods, it is recommended to visit after the next visit to a zoo also a Natural History Museums with its paleontological section.

Executive Curator
JURGEN LANGE