When they want to move as a group, meerkats call to each other. Capuchin monkeys trill. Gorillas grunt. Honeybees make what is called a piping sound.
African wild dogs sneeze. And that’s a first.
No other social animal has been reported to cast a vote, of sorts, by sneezing, although in humans sneezing may once have expressed a negative opinion, as in, “nothing to sneeze at.”
Wild dog sneezing is different. For one thing, it seems to indicate a positive reaction to a proposal before a group of dogs. When a pack of these dogs is getting ready to hunt, scientists reported, the more sneezes, the more likely they are to actually get moving.
Just about all social organisms make group decisions that require reaching a consensus. If monkeys or meerkats are looking for a better place to forage, they need to reach a consensus about moving on among a minimum number of animals — called a quorum, just like in Congress. Even some bacteria do this before releasing toxins or lighting up with bioluminescence.
Bacteria use chemical signals, but larger animals often use sounds as a way of saying, “I’m in.” However, among grunts, huffs, piping signals and others, the sneeze had not been reported as one of those signals until a group of American, British and Australian researchers published their observations of African dogs in the Proceedings of the Royal Society B.
They were studying the dogs where they live in Botswana to see how they decide to go on a hunt. Like most carnivores, the wild dogs sleep a lot. But at some point one of the pack will start what is called a rally, getting all the other members excited and milling around as if they want to play.
Sometimes the rallies are successful, and off the pack goes. Sometimes the pack members lie down and go back to sleep. Neil Jordan of the University of New South Wales in Sydney, the senior author of the report, noticed that the successful rallies there seemed to have more sneezing.
Reena Walker, then an undergraduate research technician at Brown University, set to work gathering hard data. Jordan’s perception was right. By far, the best predictor of whether the dogs would actually go on a hunt was the number of sneezes.
Unlike the one-person, one-vote rules of human elections, members of the group were not limited to one sneeze. And if a dominant pack member started a rally, fewer sneezes were needed from the other dogs to get the hunt off the ground, Walker said, noting that there was some interplay “between dominance and democracy.”
The sneezing is not the same as a human sneeze. It is a bit like the choo without the aah, an “audible, rapid forced exhalation through the nose” as Walker put it. And the scientists don’t know if it is voluntary or something that just happens, like a sneeze. So they can’t say it’s a true vote. But they can say that if you want to know if the dogs are going to move, counting sneezes is your best bet.