Dominance relationships in a group of domestic dogs (Canis lupus familiaris)

Abstract

We investigated the extent to which dominance relationships, as described for feral dogs and wolves, applied to a group of 24 neutered companion dogs at a dog daycare facility. Similar to other studies of dogs and wolves, we found significant linear dominance hierarchies based on highly unidirectional displays of submission and aggression. Submission was the most frequent, unidirectional and linear type of agonistic behaviour and, therefore, a better indicator of status than aggression or dominance displays. Aggression was low intensity, consisting mainly of ritualized threats with no physical contact, and conflicts involving physical contact were never injurious. Older dogs out-ranked younger dogs, but size was unrelated to dominance rank. Dominance relationships were more often expressed in same-sex dyads than between males and females. The coverage of dominance relationships in the daycare group was low compared to that reported for sexually intact dogs and wolves, which was probably a result of reduced competition due to neutering and other human influences. In many dyads dogs never exchanged agonistic behaviours, but bi-directional relationships were rare, and most dogs formed some dominance relationships with other dogs. Except for their low coverage, muzzle licks met the criteria for a formal display of submission. Our results suggest that dominance remains a robust component of domestic dog behaviour even when humans significantly reduce the potential for resource competition. The possible proximate benefits of dominance relationships for dogs are discussed.