| Wisent / European Bison | |
|---|---|
| Wisent in a game park near Springe | |
| Conservation status | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Family: | Bovidae |
| Genus: | Bison |
| Species: | B. bonasus |
| Binomial name | |
| Bison bonasus (Linnaeus, 1758) |
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| Subspecies | |
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| Geographic range | |
The wisent ( /ˈviːzənt/ or /ˈwiːzənt/), Bison bonasus, also known as the European bison or European wood bison, is a species of Eurasian bison. It is the heaviest surviving land animal in Europe; a typical wisent is about 2.1 to 3.1 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] It averages slightly lighter in weight that the American Bison (Bison bison), and has shorter hair on the neck, head and forequarters, but longer tail and horns.
Wisent were hunted to extinction in the wild, but they survived in Białowieża Forest, straddling the border between Belarus and Poland, until the 1920s and have since been reintroduced from captivity into several countries in Eastern Europe, all descendants of the Białowieża or lowland wisent. They are now forest-dwelling. They have few predators (besides humans), with only scattered reports from the 19th century of wolf and bear predation. Wisent were first scientifically described by Carolus Linnaeus in 1758. Some later descriptions treat the wisent 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 wisent 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.
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The modern English word is borrowed from modern German Wisent (German pronunciation: [ˈviːzɛnt]), which comes from Germanic *wisund (cf. Old Norse visundr, Old High German wisunt); the Old English word wesend from this root became extinct in premodern times.[4][5]
The Latin "bison" is borrowed from the same Germanic word.[6]
Historically, the lowland wisent's range encompassed all of western, central and southeastern Europe, extending 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 existing forests, the process proceeding from the west, south and the north. The first population to be extirpated was that of Gaul in the 8th century AD. The wisent became extinct in northern 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]
Wisent survived in Eastern Europe, although they slowly had been losing their numbers there as well. For example, the last wisent in Transylvania died in 1790. In Poland, in Białowieża Forest, wisent were legally the property of the Polish kings until the Third partition of Poland. However, there were also wild wisent herds in Poland's eastern frontier lands until the mid-17th century. Polish kings took measures to protect their wisent. King Sigismund II Augustus instituted the death penalty for poaching a wisent in Bialowieza in the mid-16th century. In the early 19th century the new lords of Bialowieza, Russian czars, retained old Polish laws protecting the wisent herd in Bialowieza. Despite these measures and others, the wisent population continued to decline over the following century, with only Bialowieza and Northern Caucasus populations surviving into the 20th century.
Most Bialowieza wisent became victims of World War I, with German troops occupying Bialowieza killing 600 of the animals for sport, meat, hides, and horns. A German scientist brought to the attention of army officers that the animals were facing imminent extinction, but at the very end of the war, retreating German soldiers shot all but 9 wisent.[8] The last wild wisent in Poland was killed in 1919, and the last wild wisent 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; first as a card index from 1923 with a full publication in 1932.[9]
Although superficially similar, there are a number of physical and behavioral differences between the wisent and the American bison. The Wisent has 14 pairs of ribs, while the American Bison has 15.[10] Adult wisents are taller than American bison, and have longer legs.[11] Wisents 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 wisent is set further forward than the forehead when the neck is in a neutral position. The body of the wisent is less hairy, though its tail is hairier than that of the American species. The horns of the wisent 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.[12] European bison are less tameable than their American cousins, and breed with domestic cattle less readily.[13]
The wisent is a herd animal, which lives in both mixed and solely-male groups. Mixed groups consist of infants, young aged 2–3 years, calves 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. Wisent 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 wisent does not defend territory, and herd ranges tend to greatly overlap. Core areas of territory are usually sited near meadows and water sources.[7]
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]
Wisent 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.[14] Wisent 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.[14] Wisent need to drink every day and in winter can be seen breaking ice with their heavy hooves.[15] Despite their usual slow movements, wisent are surprisingly agile and can clear three metre wide streams or two metre high fences from a standing start.[15][16]
The protection of the wisent has a long history; between the 15th and 18th century those in the Forest of Białowieża were protected and their diet supplemented.[17] Efforts to restore this species to the wild began in 1929, with the establishment of the Bison Restitution Centre at Białowieża, Poland.[18][19] 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
Wisent were reintroduced successfully into the wild, beginning in 1951. Białowieża Forest in Poland and Belarus is home to 800 wild wisent.[20] They are also found in forest preserves in the Western Caucasus.
Free-ranging herds are found in Poland, Lithuania, Belarus, Ukraine, Romania, Russia, Slovakia, Latvia, Kyrgyzstan, Moldova (since 2005),[21] and in Spain (since 2010).[22] There are plans to re-introduce two herds in western Germany [23] and in Oostvaardersplassen Nature Reserve in Flevoland (Netherlands). Zoos in 30 countries also have quite a few animals. There were 3,000 individuals (as of 2000), all descended from only 12 individuals. Because of their limited genetic pool, they are considered highly vulnerable to illnesses like foot and mouth disease.
Wisent have lived as long as 30[24] 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.
Wisent 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. Cattle and wisent 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.
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 wisent bulls have one of only two remaining Y-chromosomes.
This article incorporates text from the ARKive fact-file "Wisent" under the Creative Commons Attribution-ShareAlike 3.0 Unported License and the GFDL.