European bison (Bison bonasus)

Also known as: wisent
French: Bison d'Europe
GenusBison (1)
SizeLength: 2.9 m (2)
Shoulder height: 1.8 - 1.95 m (2)
Weight600 - 1,000 kg (3)

The European bison is classified as Vulnerable (VU) on the IUCN Red List (1). Within the species are two genetic lines, and the Lowland-Caucasian is classified as Endangered (EN) (1).

The European bison (Bison bonasus), or 'wisent', is similar in appearance to its North American relative (Bison bison) (4). Although smaller in size (4), it has the characteristic thickset body shape with a short neck and a pronounced shoulder hump (2). There is a longer mane of hair underneath the neck and also on the forehead (2). The dense coat is dark to golden brown in colour (2), but is less shaggy than that of the American bison (4). Both sexes bear short horns that project outwards and then curve up (2).

Previously roaming throughout western, central and southeastern Europe, by the beginning of the 20th Century the European bison persisted only in two protected ancient forests in Poland and the former Soviet Union (5) (6). By 1927, the species had been lost from the wild entirely and only 54 individuals survived in European Zoos (6). There have been re-introductions to forests in Belarus, Poland, Russia, Lithuania, the Ukraine and Slovakia (6).

The European bison inhabits mixed and deciduous forests, with undergrowth and open spaces (7) (8).

European bison have a similar social system to their American relatives, and are believed by some to represent the same species (9). Outside of the mating season the males form bachelor herds, whilst females and their young are found in maternal groups of 13 to 15 individuals (2). These female groups occupy vast home ranges of up to 100 square kilometres and are led by a dominant cow (6). The 'rutting' season takes place between August and October and during this time males join up with the female herds and compete for access to receptive females (6). Once an appropriate cow has been found, the bull will attempt to separate the female from the remaining herd and particularly from the advances of other males in the group (4). He will attend to her in this way for around a day before mating (4). Aggressive clashes between rival males may occur at this time. Cows give birth after a gestation period of about 264 days, typically in May and July, usually leaving their herd to do so; young calves are able to run after only a few hours of being born and are fully weaned at around one year old (6).

Bison feed predominantly on grasses although they will also browse on shoots and leaves; in summer months, an adult male can consume 32 kilograms of food in a day (6). Bison in the Bialowieza Forest in Poland have traditionally been fed hay in the winter for centuries, and vast herds may gather around this diet supplement (6). Bison need to drink every day and in winter can be seen breaking ice with their heavy hooves (2). Despite their usual slow movements, bison are surprisingly agile and can clear three metre wide streams or two metre high fences from a standing start (2) (3).

With the advance of agriculture, vast tracts of the European bison's habitat were lost and their range became massively restricted (6). These animals were also persecuted by hunting and in 1927 the species finally became Extinct in the Wild (6). Re-introductions of the bison to some of its former range have proved extremely successful and, due to the natural low mortality of the species, it has even been necessary to cull some populations in order to manage them effectively (6).

The protection of the European bison has a long history; between the 15th and 18th Century those in the Forest of Białowieża were protected and their diet supplemented (4). Efforts to restore this species to the wild began in 1929, with the establishment of the Bison Restitution Centre at Białowieża, Poland (7) (8).  Subsequently, in 1948, the Bison Breeding Centre was established within the Prioksko-Terrasny Biosphere Reserve (10). Re-introductions of captive-bred individuals to the wild began in 1952 in the Polish part of Białowieża, followed in 1953 at the Byelorussian side. Re-introductions to date have occurred in Belarus, Poland, Russia, Lithuania, Slovakia and the Ukraine (6). The aim of the Bison Specialist Group of the World Conservation Union (IUCN) is to establish a total free-ranging population of around 6,000 animals from two different lineages (5). A European network of breeders and owners was established and a coordinated program for saving the genetic variability within the captive part of the species is organized, as well as planned re-introductions (European Bison Conservation Centre) (3).The re-introduction of the European bison represents a remarkable conservation success story.

For more information on the bison:

Authenticated (02/03/2011) by Dr Wanda Olech, Co-Chair of the IUCN Bison Specialist Group

  1. IUCN Red List (January, 2009)
  2. Ultimate Ungulate (November, 2002)
  3. Olech, W. (March, 2011) Pers. comm.
  4. Animal Diversity Web (November, 2002)
  5. Pucek, Z., Udina, I., Seal, U.S. and Miller, P. (1996) Population and habitat viability assessment for the European bison (Bison bonasus). IUCN/SSC Conservation Breeding Specialist Group, Apple Valley, Minnesota.
  6. Pucek, Z., Belousova, I.P., Krasiñska, M., Krasiñski, Z.A. and Olech, W. (2004) European Bison Status Survey and Conservation Action Plan. IUCN/SSC Bison Specialist Group, Gland, Switzerland and Cambridge, UK.
  7. Krasińska, M. and Krasiński, Z. (2007) European bison - the nature monograph. Mammal Research Institute, Białowieża, Poland.
  8. Macdonald, D. (2001) The New Encyclopedia of Mammals. Oxford University Press, Oxford.
  9. Burnie, D. (2001) Animal. Dorling Kindersley, London.
  10. Bison Specialist Group (November, 2002)