When moving as a group, each bison in a herd can "vote" on which direction to take, and the decision will depend on the majority, just like in elections, according to a report published by scientists in the forthcoming issue of Animal Behaviour.
Researchers concluded this while observing the herd movements of about 30 European bison in Southern France's Monts d'Azur reserve. This species of bison, also known as wisent, is more slender than its American cousin and prefers forests over plains. It nearly became extinct in the 20th century, and small herds are now being reintroduced across Europe. Because farmers were concerned that the herbivores could damage their land, scientists launched this research to better understand the animal's movements.
Thanks to hours of observation backed by statistical analyses, they found that, whatever its age or gender, any bison could suggest the herd's next direction. But the results show that the "votes" of female adults are both most frequent and most successful. This could be explained by the need among female bison to conserve energy for their milk production.
"Only when a sufficient number of animals express their preference will the movement be launched," Le Temps quoted researcher Cédric Sueur as saying. According to the study, a suggested direction is also more likely to be approved if the leading bison chooses the direction most of the herd was already facing. In the human world, this could almost be labeled a Hobson's choice.
Such behaviors, which have also been observed in hamadryas baboons, Tonkean macaques and African buffalos, help maintain group cohesion and stability. "If the organization was too despotic, some animals would leave the group, and it would lose its benefits, especially regarding protection against predators," Sueur told Le Temps.