Wild horses became extinct in the 18^th century. Nowadays wild horses were back-bred by the brothers Heck in the 1930s. They are similar to wild horses originally inhabiting the forests on the western flanks of the Ural. Continuing deforestation, due to increasing agricultural development, destroyed their natural habitat, leading to their eradication.

Wisent originally lived in the woods; but once again the destruction of their natural habitat nearly led to their eradication. Some animals survived in captivity, and so the stock was preserved through purposeful breeding. Today, there are more than 3000 wisents worldwide; some of them were reintroduced into the wild.

Aurochs' originally inhabited most parts of Europe, northern Africa and western Asia. The animals lived in the steppes, wooded areas and mountainous regions. They became extinct in the 17^th century. As for the tarpans, the brothers Heck recreated the “Heck cattle”-aurochs by crossbreeding.