Bisonoxe höjd
10 stora och små fakta om bisonoxar du inte visste
Bisonoxen är ett kraftigt djur med en kroppslängd mellan 2,10 och 3,50 meter (huvud och bål). Därtill kommer en 30 till 60 cm (sällan upp till 90 cm) lång svans och mankhöjden ligger mellan 1,50 och 1,95 meter. Med en vikt som vanligen ligger mellan och kilogram är den det största nu levande landdjuret i Nordamerika.
A bison pl. Two extant and numerous extinct species are recognised. Of the two surviving species, the American bison , B. Although colloquially referred to as a buffalo in the United States and Canada, [ 2 ] it is only distantly related to the true buffalo. The North American species is composed of two subspecies, the Plains bison , B. A third subspecies, the eastern bison B. The European bison , B.
While bison species have been traditionally classified in their own genus , modern genetics indicates that they are nested within the genus Bos , which includes, among others, cattle, yaks and gaur , being most closely related to yaks. Bison are sometimes bred with domestic cattle and produce offspring called beefalo , in North America, or żubroń , in Poland. The American bison and the European bison wisent are the largest surviving terrestrial animals in North America and Europe.
They are typical artiodactyl cloven hooved ungulates, and are similar in appearance to other bovines such as cattle and true buffalo. They are broad and muscular with shaggy coats of long hair.
Bisonoxen vandrar åter i västra USA
Adults grow up to 2 metres 6 feet 7 inches in height and 3. Bison are nomadic grazers and travel in herds. The bulls leave the herds of females at two or three years of age, and join a herd of males, which usually are smaller than female herds. Mature bulls rarely travel alone. Towards the end of the summer, for the reproductive season, the sexes necessarily commingle. American bison are known for living in the Great Plains , but formerly had a much larger range, including much of the eastern United States and parts of Mexico.
Both species were hunted close to extinction during the 19th and 20th centuries, but have since rebounded. The wisent in part owes its survival to the Chernobyl disaster, as the Chernobyl Exclusion Zone has become a kind of wildlife preserve for wisent and other rare megafauna such as the Przewalski's horse , though poaching has become a threat in recent years. Genetically pure B. Although superficially similar, physical and behavioural differences exist between the American and European bison.
The American species has 15 ribs, while the European bison has The American bison has four lumbar vertebrae, while the European has five. Adult American bison are less slim in build and have shorter legs. Their anatomies reflect this behavioural difference; the American bison's head hangs lower than the European's. The body of the American bison is typically hairier, though its tail has less hair than that of the European bison.
The horns of the European bison point 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 butting. The bovine tribe Bovini split about 5 to 10 million years ago into the buffalos Bubalus and Syncerus and a group leading to bison and taurine cattle. While nuclear DNA indicates that both extant bison species are each other's closest living relatives, the mitochondrial DNA of European bison is more closely related to that of domestic cattle and aurochs while the mitochondrial DNA of American bison is closely related to that of yaks.
This discrepancy is either suggested to be the result of incomplete lineage sorting or ancient introgression. The earliest members of the bison lineage, known from the Late Pliocene to Early Pleistocene of the Indian Subcontinent Bison sivalensis and China Bison palaeosinensis , approximately 3. The oldest remains of Eobison in Europe are those Bison georgicus found in Dmanisi , Georgia, dated to around 1.
More derived members of the genus are placed in the subgenus Bison Bison , which first appeared towards the end of the Early Pleistocene, around 1. The steppe bison Bison priscus first appeared during the mid- Middle Pleistocene in eastern Eurasia, and subsequently became widely distributed across Eurasia. Its relationship with other extinct bison species is unclear, though it appears to be only distantly related to the steppe and American bisons, with possibly some interbreeding between the two lineages during the Middle Pleistocene.
During the population bottleneck caused by the great slaughter of American bison during the 19th century, the number of bison remaining alive in North America declined to as low as During that period, a handful of ranchers gathered remnants of the existing herds to save the species from extinction. These ranchers bred some of the bison with cattle in an effort to produce "cattleo" [ 27 ] today called " beefalo ".
Accidental crossings were also known to occur. Generally, male domestic bulls were crossed with bison cows, producing offspring of which only the females were fertile. The crossbred animals did not demonstrate any form of hybrid vigor , so the practice was abandoned. Wisent-American bison hybrids were briefly experimented with in Germany and found to be fully fertile 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.