Zimbru
European bison survived in a few natural forests in Europe, but their numbers dwindled. In the Polish–Lithuanian Commonwealth, European bison in the Białowieża Forest were legally the property of the Grand Dukes of Lithuania 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, after the partitions of the Polish Commonwealth the Russian tsars retained old Lithuanian 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. The last European bison in Transylvania died in 1790.