Once the majority of the group has voted, the remaining undecided voters simply side with the majority, walking along but not turning back to monitor the others. Those who opted for the losing recommendation turn around and catch up the group.
Like most primates, Tonkean macaques maintain a strict social hierarchy, but all group members vote when it comes to these sorts of decisions. And any individual may act as initiator, regardless of age, sex, or hierarchical status. By contrast, it is primarily the older or more dominant individuals who make decisions for other monkey species, such as the closely related rhesus macaques.
Democracy in this form is not limited to primates. African buffalo (Syncerus cafer) are large bovines distantly related to domestic cows that can be found grazing in forests, grasslands and swamps across the African continent. Food patches vary for African buffalo, based on previous grazing history by the herd as well as by other species, on the speed at which plants regrow, and on soil quality – not to mention the amount of time it would take them to get there.
Writing in The American Naturalist, David Sloan Wilson quotes a buffalo expert named H. H. T. Prins, who wrote about an odd pattern in which the females get up while at rest, shuffle around, and lay back down. "[A]t first I interpreted this as “stretching the legs”, but one day I noticed that the cows adopt a particular stance after the shuffling and before lying down again,” he wrote. “They seem to gaze in one direction and keep their head higher than the normal resting position but lower than the alert… This standing up, gazing and lying down behaviour continues for about an hour, but the overall impression remains that of a herd totally at rest." Wilson notes that Prins spent two years watching the buffalo before realising that this simple stretching behaviour was actually a means of registering one's vote. Prins continues (as quoted by Wilson): "A few moments later, everywhere in the herd buffalo start trekking. The exciting thing is that they start trekking, at the beginning independently of each other, in the same direction."
Rather than simply shifting positions to become more comfortable, the female buffalo were actually casting their votes to indicate the direction they wished to travel. And the direction that the herd ultimately chose to move could be successfully predicted by the number of individuals who had initially been gazing that way. In other words, herd movements are guided by majority vote. If the votes were evenly divided between two directions, then the herd separates for the night, grazing at different locations, and reconvenes in the morning.
Unlike the Tonkean macaques, only the adult female African buffalo are allowed to vote. But like the monkeys, all adult females vote regardless of their position within the dominance hierarchy. Also like the monkeys, any female may propose a travel route.
One thing animals don't appear to do, though, is explicitly select their leaders, as humans do. For elephants, it’s automatically the oldest female. Chimpanzees are led by the male who is able to retain hold over his position as most dominant. A female honey bee becomes queen based on what she eats in the first days of her life (though worker bees do seem to have some influence over who becomes queen, giving honey bees the most human-like election process).
But group decision-making is not unique to our species. Even the smallest worker bee, the youngest Tonkean macaque, and the least dominant African buffalo get an equal say in making group decisions that directly impact their own survival. Democracy, it seems, is far from being uniquely human.