Among the most admired and feared hunters, the African wild dog or painted dog appears in the forefront of cooperative packs. With dominants governing the reproductive side of society, the organisation of the pack before collective movement is very interesting. Reena H Walker and her colleagues from the Botswana Predator Conservation Trust, and the Universities of Swansea, UK, New South Wales, Australia and Brown University, US, publish today with “Sneeze to leave: African wild dogs (Lycaon pictus) use variable quorum thresholds facilitated by sneezes in collective decisions.” The Proceedings of the Royal Society B provide the paper here.
The original interest lay in the decision making that took place in “rallies,” resulting in movement of 5 packs, living in the Okavango Delta, Botswana A quorum is the number of animals required to somehow support the potential hunt or decide to abandon the idea. These quora are found in several animals such as meerkats. The capuchin monkey, Cebus capucinus or even in honeybees. In such a sociable dog species, the non-aggressive nature of group living in such a feared killer is remarkable. Pups for example normally feed directly at kill-sites. Previously the attitude of the dogs has been called a shared consensus, but that does not reveal how decisions are made for hunting preparations.
The key to the decision is the abrupt exhalation of air which the authors call a sneeze. These sneezes were observed during rallies to signal departure or act as a cue. But were they a voting mechanism taking place at an actual quorum?
Dominance and other social influences have an obvious effect on the decision to depart or not, as will the number of hunts that the pack have already been involved in. The sneezes were meticulously recorded, despite the thick bush that dogs habitually rest in, and 3 types of social interaction noted as head-touching or approach (Greet), running flank-to-flank (Parallel Run) and more than 3 situated 1m from each other (Mob.) Dominance was recorded as the right of access to a kill.
Dingoes display a “snuff” reaction in response to disturbances or anxiety, with coyotes using a “huff” to communicate low-level threats, but the sneeze voting system has no parallel among the dog species. As Lycaon has possibly the lowest aggression within the group, the sneeze seems to hold no threat, but it is used as an explicit part of the joint decision-making process. Other species may now reveal similar behaviours with mountain gorillas and their increased grunt levels resembling this movement directive most closely! The other occasion on which Reena and her colleagues noticed a sneeze was during a resting period, but the exact context of the sneeze becomes more obvious during a rally when 3 sneezes from a dominant or 10 sneezes from a lower-rank will initiate collective movement of the pack.
More interest will be stimulated from this paper, as social interactions among many animals become better studied. Video photography and tracking collars are helped here by the distinct beautiful pelage of the dog coats. Identification of the individuals in some species requires intricate labelling, but Lycaon pictus comes with ready-made ID. We look forward especially to some work with other endangered dog species such as the dhole (Cuon alpinus) or the South American bush dog (Speothos venaticus.)