TWIL #063 - Cape Buffalo Herds Vote on Which Direction to Travel
When a cape buffalo herd needs to move, females stand up, face a direction, and sit back down. The direction with the most votes wins. This distributed decision-making has been formally studied.
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The Cape buffalo (Syncerus caffer) is one of Africa's most formidable animals - adult males weigh up to 850 kg, have never been successfully domesticated, and are responsible for more human fatalities annually than lions. They are also, it turns out, surprisingly democratic.
The voting behaviour: A 2011 study by Larissa Conradt and Timothy Roper, published in Proceedings of the Royal Society B, documented a remarkable decision-making ritual in Cape buffalo herds. During rest periods, females stand up, look in a direction they prefer to travel, then sit back down. After a period in which multiple females do this, the herd moves in the direction that received the most "votes."
Males do not participate in the vote, despite being dominant in most other social contexts. The decision is driven by experienced females who know the landscape and the location of water sources. The herd aggregates this distributed knowledge by observing the directional cues of individuals.
Why collective decision-making: In large groups, no single individual has complete information. Distributing the decision across experienced members reduces the risk of the entire herd following a single animal's mistake. The more individuals that align on a direction, the more likely that direction reflects genuine environmental knowledge rather than random preference.
"The Black Death": Buffalo have a reputation among big game hunters as one of the most dangerous quarry in Africa. They are known to circle back on hunters who have wounded them and ambush from behind, and they have been recorded holding grudges - returning to an attack site. Their horns form a continuous solid shield called a boss across the forehead, which makes frontal attacks dangerous even for lions.
Predator defence: Against lions, buffalo form defensive circles with calves in the centre. They will cooperate aggressively to rescue herd members being attacked - including running back to drive off lions mid-kill, something rarely seen in other prey species.