There are two living species of bison, the European bison and the American bison. In addition there are four known extinct species of bison. The European bison (Bison bonasus), also known as wisent (pron.: /ˈviːzənt/ or /ˈwiːzənt/) or the European wood bison, is the Eurasian species of bison.

European bison were hunted to extinction in the wild, with the last wild animals being shot in the Białowieża Forest in Eastern Poland in 1919 and in the Western Caucasus in 1927, but have since been reintroduced from captivity into several countries in Europe, all descendants of the Białowieża or lowland European bison. They are now forest-dwelling. They have few predators (besides humans), with only scattered reports from the 19th century of wolf and bear predation. European bison were first scientifically described by Carolus Linnaeus in 1758. Some later descriptions treat the European bison as conspecific with the American bison. It is not to be confused with the aurochs, the extinct ancestor of domestic cattle.

In 1996 the IUCN classified the European bison as an endangered species. It has since been downgraded to a vulnerable species. In the past it was commonly killed to produce hides and drinking horns, especially during the Middle Ages.

Description

The European bison is the heaviest surviving wild land animal in Europe; a typical European bison is about 2.1 to 3.5 m (7 to 10 ft) long, not counting a tail of 30 to 60 cm (12 to 24 in) long, and 1.6 to 2 m (5 to 7 ft) tall. Weight typically can range from 300 to 920 kg (660 to 2,000 lb), with an occasional big bull to 1,000 kg (2,200 lb) or more.^[2][3][4] On average, it is slightly lighter in body mass and yet taller at the shoulder than the American bison (Bison bison). Compared to the American species, the Wisent has shorter hair on the neck, head and forequarters, but longer tail and horns.

Etymology

The modern English word wisent was borrowed in the 19th century from modern German Wisent [ˈviːzɛnt], itself from Old High German wisunt, wisant, related to Old English wesend, weosend and Old Norse vísundr. The Old English cognate disappeared as the bison's range shrank away from English-speaking areas by the late Middle Ages.^[5][6]

The English word bison was borrowed ca. 1611^[5] from Latin bisōn (pl. bisontes), itself from Germanic. The root *wis-, also found in weasel, originally referred to the animal's musk.

History

A dead specimen of the now-extinct Caucasian subspecies, 1889

Holocene range (light green), range in the high middle ages (dark green) and relict populations in the early 20th century (red)

European bison's skeleton

Historically, the lowland European bison's range encompassed all lowlands of Europe, extending from the Massif Central to the Volga River and the Caucasus. It may have once lived in the Asiatic part of what is now the Russian Federation. Its range decreased as human populations expanded cutting down forests. The first population to be extirpated was that of Gaul in the 8th century AD. The European bison became extinct in southern Sweden in the 11th century, and southern England in the 12th. The species survived in the Ardennes and the Vosges until the 15th century.^[7] In the early middle ages, the wisent apparently still occurred in the forest steppes east of the Ural, in the Altay Mountains and seems to have reached Lake Baikal in the east. The northern boundary in the Holocene was probably around 60°N in Finland.^[8]

European bison survived in a few natural forests in Europe but its numbers dwindled. The last European bison in Transylvania died in 1790. In Poland, European bison in the Białowieża Forest were legally the property of the Polish kings until the Third partition of Poland. Wild European bison herds also existed in the forest until the mid-17th century. Polish kings took measures to protect the bison. King Sigismund II Augustus instituted the death penalty for poaching a European bison in Białowieża in the mid-16th century. In the early 19th century, Russian czars retained old Polish laws protecting the European bison herd in Białowieża. Despite these measures and others, the European bison population continued to decline over the following century, with only Białowieża and Northern Caucasus populations surviving into the 20th century.

During World War I, occupying German troops killed 600 of the European bison in the Białowieża Forest for sport, meat, hides, and horns. A German scientist informed army officers that the European bison were facing imminent extinction, but at the very end of the war, retreating German soldiers shot all but 9 animals.^[9] The last wild European bison in Poland was killed in 1919, and the last wild European bison in the world was killed by poachers in 1927 in the western Caucasus. By that year fewer than 50 remained, all in zoos.

To help manage this captive population, Dr. Heinz Heck commenced the first studbook for a non-domestic species, initially as a card index in 1923 leading to a full publication in 1932.^[10]

Genetic history

A 2003 study of mitochondrial DNA indicated four distinct maternal lineages in tribe Bovini:

1. taurine cattle and zebu,
2. wisent,
3. American bison and yak, and
4. banteng, gaur, and gayal.

However, Y chromosome analysis associated wisent and American bison.^[11] An earlier study using amplified fragment length polymorphism (AFLP) fingerprinting showed a close association of wisent and American bison and probably with yak, but noted that the interbreeding of Bovini species made determining relationships problematic.^[12]

Skulls of European bison (left) and American bison (right)

Wisent-American bison hybrids were briefly experimented with in Germany and a herd of such animals is maintained in Russia. A herd of cattle-wisent crossbreeds (Zubron) is maintained in Poland. First-generation crosses do not occur naturally, requiring caesarean delivery. First-generation males are infertile.

Differences from American bison

Although superficially similar, there are a number of physical and behavioural differences between the European bison and the American bison. The European bison has 14 pairs of ribs, while the American Bison has 15.^{[13][dubious – discuss]} Adult European bison are (on average) taller than American bison, and have longer legs.^[14] European bison tend to browse more, and graze less than their American cousins, due to their necks being set differently. Compared to the American bison, the nose of the European bison is set further forward than the forehead when the neck is in a neutral position. The body of the European bison is less hairy, though its tail is hairier than that of the American species. The horns of the European bison point forward through the plane of their faces, making them more adept at fighting through the interlocking of horns in the same manner as domestic cattle, unlike the American bison, which favours charging.^[15] European bison are less tameable than their American cousins, and breed with domestic cattle less readily.^[16]

Behaviour and biology

Social structure and territorial behaviours

The European bison is a herd animal, which lives in both mixed and solely male groups. Mixed groups consist of adult females, calves, young aged 2–3 years, and young adult bulls. The average herd size is dependent on environmental factors, though on average, they number 8-13 animals per herd. Herds consisting solely of bulls are smaller than mixed ones, containing two individuals on average. European bison herds are not family units. Different herds frequently interact, combine and quickly split after exchanging individuals.^[7]

Territory held by bulls is correlated by age, with young bulls aged between 5–6 tending to form larger home ranges than older males. The European bison does not defend territory, and herd ranges tend to greatly overlap. Core areas of territory are usually sited near meadows and water sources.^[7]

Reproduction

The rutting season occurs from August through to October. Bulls aged 4–6 years, though sexually mature, are prevented from mating by older bulls. Cows usually have a gestation period of 264 days, and typically give birth to one calf at a time.^[7]

On average, male calves weigh 27.6 kg (60.8 lb) at birth, and females 24.4 kg (53.8 lb). Body size in males increases proportionately to the age of 6 years. While females have a higher increase in body mass in their first year, their growth rate is comparatively slower than that of males by the age of 3–5. Bulls reach sexual maturity at the age of two, while cows do so in their third year.^[7]

Diet

European 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.^[17] European bison in the Białowieża Forest in Poland have traditionally been fed hay in the winter for centuries, and vast herds may gather around this diet supplement.^[17] European bison need to drink every day and in winter can be seen breaking ice with their heavy hooves.^[18] Despite their usual slow movements, European bison are surprisingly agile and can clear three metre wide streams or two metre high fences from a standing start.^[18][19]

Conservation

A European bison at Skansen, a herd established in the 1890s.

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.^[20] Efforts to restore this species to the wild began in 1929, with the establishment of the Bison Restitution Centre at Białowieża, Poland.^[21][22] Subsequently, in 1948, the Bison Breeding Centre was established within the Prioksko-Terrasny Biosphere Reserve. On April 24, 2011 five bison were introduced in Pleistocene Park a project of recreating the steppe ecosystem altered 10,000 years ago

Reintroduction

Beginning in 1951, European bison have been reintroduced into the wild. Free-ranging herds are currently found in Poland, Lithuania, Belarus, Ukraine, Romania, Russia, Slovakia, Latvia, Kyrgyzstan, and in forest preserves in the Western Caucasus. Białowieża Forest — an ancient woodland that straddles the border between Poland and Belarus — is now home to 800 wild individuals.^[23] Herds have also been introduced in Moldova (2005),^[24] Spain (2010),^[25] and in Denmark (2012).^[26]

There are plans to re-introduce two herds in Germany^[27] and in Oostvaardersplassen Nature Reserve^[28] in Flevoland (Netherlands), and in 2007 a bison pilot project in a fenced area was begun in Kraansvlak.^[29] Zoos in thirty countries also have quite a few animals. As of 2000, there were 3,000 individuals, all descended from only 12 individuals. Because of their limited genetic pool, they are considered highly vulnerable to illnesses like foot-and-mouth disease.

Since the 1983 a small reintroduced population lives in the Altai Mountains. This population suffers from inbreeding depression and needs the introduction of unrelated animals for "blood refreshment". In the long term, authorities hope to establish a population of about 1000 animals in the area. The Altai population is the easternmost population and the only one in Siberia. The northernmost current population of the European bison lives in the Vologodskaya Oblast in the North Dvina river valley at about 60°N. It survives here without supplementary winter feeding. Another Russian population lives in the forests around the Desna River ot the border between Russia and Ukraine.^[8]

In June 2012 one male and six females were moved to the Danish island of Bornholm. The plan is to release these animals into the wild after five years of adjusting to the island's environment, after which it is hoped they will help biodiversity by maintaining open grassland.^[30]

Miscellanea

A male European bison in Minsk Zoo.

European bison have lived as long as 30^[31] years in captivity, although in the wild their lifespan is shorter. Productive breeding years are between four and 20 years of age in females, and only between six and 12 years of age in males. Wisent occupy home ranges of as much as 100 km² (40 sq mi) and some herds are found to prefer meadows and open areas in forests.

European bison can cross-breed with American bison. The products of a German interbreeding program were destroyed after World War II. This programme was related to the impulse which created the Heck cattle. The cross-bred individuals created at other zoos were eliminated from breed books by the 1950s. A Russian back-breeding program resulted in a wild herd of hybrid animals, which presently lives in the Caucasian Biosphere Reserve (550 individuals in 1999).

There are also wisent-cattle hybrids, similar to North America beefalo. Cattle and European bison can hybridise fairly readily, but the calves cannot be born naturally (birth is not triggered correctly by the first-cross hybrid calf, and they must therefore be delivered by Caesarian section). In 1847, a herd of wisent-cattle hybrids named żubroń was created by Leopold Walicki. The animals were intended to become durable and cheap alternatives to cattle. The experiment was continued by researchers from the Polish Academy of Sciences until the late 1980s. Although the program resulted in a quite successful animal that was both hardy and could be bred in marginal grazing lands, it was eventually discontinued. Currently the only surviving żubroń herd consists of just a few animals in Białowieża Forest, Poland and Belarus.

The modern herds are managed as two separate lines – one consisting of only Bison bonasus bonasus (all descended from only seven animals) and one consisting of all 12 ancestors including the one Bison bonasus caucasicus bull. Only a limited amount of inbreeding depression from the population bottleneck has been found, having a small effect on skeletal growth in cows and a small rise in calf mortality. Genetic variability continues to shrink. From five initial bulls, all current European bison bulls have one of only two remaining Y-chromosomes.^{[citation needed]}

See also

This "see also" section may contain an excessive number of suggestions. Please ensure that only the most relevant suggestions are given and that they are not red links, and consider integrating suggestions into the article itself. (January 2013)

• Society for the Protection of the European Bison
• Carpathian wisent
• Caucasian wisent
• Steppe wisent

References

This article incorporates text from the ARKive fact-file "European bison" under the Creative Commons Attribution-ShareAlike 3.0 Unported License and the GFDL.