Wild Dogs Sneeze to Decide Whether They're Ready to Hunt
These highly social carnivores make group decisions at "social rallies."
Posted Sep 07, 2017
It's always a pleasure to write about unique research projects that offer surprising results. Just yesterday, I learned about a new study by Reena Walker and her colleagues published in The Proceedings of the Royal Society B titled "Sneeze to leave: African wild dogs (Lycaon pictus) use variable quorum thresholds facilitated by sneezes in collective decisions." Ms. Walker and her colleagues studied five packs and 68 greeting ceremonies, called social rallies, of these highly endangered carnivores living in and around the Moremi Game Reserve in the Okavango Delta in Botswana.
This exciting new essay is available online. Its abstract reads:
In despotically driven animal societies, one or a few individuals tend to have a disproportionate influence on group decision-making and actions. However, global communication allows each group member to assess the relative strength of preferences for different options among their group-mates. Here, we investigate collective decisions by free-ranging African wild dog packs in Botswana. African wild dogs exhibit dominant-directed group living and take part in stereotyped social rallies: high energy greeting ceremonies that occur before collective movements. ... We show that the probability of rally success (i.e. group departure) is predicted by a minimum number of audible rapid nasal exhalations (sneezes), within the rally. Moreover, the number of sneezes needed for the group to depart (i.e. the quorum) was reduced whenever dominant individuals initiated rallies, suggesting that dominant participation increases the likelihood of a rally's success, but is not a prerequisite. As such, the ‘will of the group’ may override dominant preferences when the consensus of subordinates is sufficiently great. Our findings illustrate how specific behavioural mechanisms (here, sneezing) allow for negotiation (in effect, voting) that shapes decision-making in a wild, socially complex animal society.
Sneezes indicate a quorum
If you'd like to see these social rallies, a video can be seen in an essay called "Swansea Uni study: African wild dogs 'sneeze to vote.'
All in all, the researchers discovered that the more sneezes there were, the more likely it was that the group would head off on a hunt. Additionally, the dominance rank of the sneezers was important to consider. When the dominant male and female were part of the rally, fewer sneezes were needed before the pack began hunting. So, rank had clout.
The researchers concluded, "Our study is the first to quantitatively assess behaviour and decision-making processes in African wild dog pre-departure rallies. We found that sneezes, a previously undocumented unvoiced sound in the species, are positively correlated with the likelihood of rally success preceding group movements and may function as a voting mechanism to establish group consensus in an otherwise despotically driven social system."
Please stay tuned for more exciting research on the social behavior of the fascinating nonhuman animals with whom we share our magnificent planet. Who would have thought that messages communicated through sneezing would provide important social cues that influenced group decisions to do something or not. I hope that more comparative research will show just how applicable these findings are to other species.