Threatened species of Bison bonasus

The European bison Bison bonasus, also called the wisent, and zubr (zshoobr) in Poland, once roamed the great temperate, deciduous forest biome that stretched from the British Isles, through most of Europe and into Siberia. The once continuous distribution of bison has been fragmented into a few isolated areas. There are two extant subspecies - the lowland bison Bison bonasus bonasus and the highland or Caucasus bison Bison bonasus caucasus, yet there are no remaining pure Caucasus stock -- they were intermixed with lowland bison and, in some cases, the American bison Bison bison before they went extinct in the wild. The original distribution consisted of three subspecies, but today only the lowland pedigree and Caucasus hybrid remains.

The herds are managed as two separate lineage and kept isolated to prevent interbreeding.

The lowland bison today consists of about 1,000 animals, with 69% free ranging in Poland, Belarus, Russia, Lithuania, Romania, and Ukraine. The others exist in zoos, private preserves, and breeding stations. The Caucasus subspecies is made up of about 2,200 animals, roughly half of which are wild. The largest concentration live in Poland's Bialowieza National Park. It is here that Europe's last remaining primaeval forest stands. The National Park covers an area of about 52 square kilometres, which is located within the larger (and lesser protected) Bialowieza forest (570 sq km) and contiguous with Belarus' Beloveskaja Pusca National Park (870 sq km).