American bison were driven from 30 million to fewer than 1,000 individuals by 1890. Zoo and conservation herd programs have helped restore populations while raising important captive welfare considerations.
Bison welfare in conservation herds requires large areas of appropriate grassland habitat for natural grazing behavior, wallowing, and herd movement. Zoo bison in small exhibits cannot express natural ranging behavior, making exhibit design focused on complexity and social appropriateness essential. Bison are highly seasonal in behavior — rutting season involves intense social competition requiring space for males to compete safely. Health management including parasite control and disease monitoring must be achieved with minimal handling to avoid severe capture stress in these powerful animals. Prairie restoration programs providing large natural areas for bison herds offer significantly better welfare outcomes than small zoo exhibits while also contributing to ecosystem restoration.