Bison “Vote” on the Direction They'd Like the Herd to Move

Every few years Americans in major cities elect a mayor. The process is relatively straightforward: we vote, and the candidate who carries the majority wins. The same goes for certain bovines. Ecologist Amandine Ramos of the French National Center for Scientific Research (CNRS) spent three months observing a bison herd at the Monts-d'Azur Biological Reserve, about 20 miles from Nice. It turns out that European bison operate by majority rule.

These individuals “cast a vote” for the direction they would like to move by orienting their bodies, Ramos observed. If they want to graze in a meadow, they face the meadow. If they would rather slake their thirst, they turn toward a water hole. Eventually one bison makes a move. If the initiator advances in the direction preferred by most herd members, the group follows. If the initiator chooses a less popular option, few follow, and the group might split for a brief period. Anyone can initiate a movement, although adult females typically garner the largest number of followers. In essence, the initiator with the most votes wins and ends up leading most of the herd. The study was published recently in the journal Animal Behaviour.

The findings could help wildlife managers reduce conflict among farmers and bison, which frequently raid crops. By outfitting those individuals likely to be leaders with collars that deliver a mild shock, managers may be able to effectively control an entire herd.

European bison are not the only nonhuman species that make decisions collectively. The behavior has also been observed in animals ranging from other ungulates such as African buffalo to primates such as Tonkean macaques. For Ramos, the study is a reminder that “communication and consensus are two processes that also exist in the animal kingdom.” Democracy, or at least a form of it, is not unique to Homo sapiens americanus.