European bison (wisent) were hunted to extinction in the wild by 1927; reintroduction programs have restored wild populations, offering welfare and ecological lessons for future megafauna recovery.
Reintroduced bison face a transition period during which welfare monitoring is particularly important. Released animals must establish home ranges, learn foraging strategies, and form social groups without the social transmission of knowledge from experienced wild conspecifics. Disease transmission from domestic cattle is a welfare and genetic risk requiring careful management. Winter supplementary feeding in some programs helps bison through periods of food shortage while populations reach densities that support natural foraging. Long-term population monitoring shows that bison in established reintroduced populations achieve welfare outcomes comparable to wild populations.