title: Down but not out: supine postures as facilitators of play in domestic dogs.
abstract: We used two sets of videotaped data of playing domestic dog dyads to determine whether rolling over during play served as a signal of submission or whether it was a combat maneuver adopted as part of an ongoing play sequence. Our results provide strong support for the latter. In the absence of any overt indication of agonism, the frequency with which rollovers occurred was determined primarily by play bout length. The discrepancy in partner size had no effect on the probability that rollovers would occur and there was no evidence that smaller dogs were more likely to rollover or to sustain a supine posture for longer, if they did. The supine phase of rollovers was significantly skewed to short durations. Most rollovers were either defensive (evading a nape bite) or offensive (launching an attack). None could be categorized as submissive. We conclude that asymmetries in the performance of rollovers cannot be assumed to point to asymmetries in the relationships between play partners. This article is part of a Special Issue entitled: Canine Behavior.
authors.affiliation: Department of Psychology, The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada; Department of Neuroscience, The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada. Electronic address: kerrimn85@gmail.com.
authors.forename: Kerri
authors.initials: K
authors.lastname: Norman
authors.affiliation: Department of Psychology, The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada; Department of Neuroscience, The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada. Electronic address: pellis@uleth.ca.
authors.forename: Sergio
authors.initials: S
authors.lastname: Pellis
authors.affiliation: Department of Psychology, The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada; Applied Behavioural Ecology and Ecosystems Research Unit, Department of Environmental Sciences, University of South Africa, P.B. X6, Florida 1710, South Africa. Electronic address: louise.barrett@uleth.ca.
authors.forename: Louise
authors.initials: L
authors.lastname: Barrett
authors.affiliation: Department of Psychology, The University of Lethbridge, 4401 University Drive, Lethbridge, Alberta T1K 3M4, Canada; Applied Behavioural Ecology and Ecosystems Research Unit, Department of Environmental Sciences, University of South Africa, P.B. X6, Florida 1710, South Africa. Electronic address: peter.henzi@uleth.ca.
authors.forename: S
authors.initials: S
authors.lastname: Peter Henzi
mesh_terms: D000374:Aggression / Q000502:physiology; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D004285:Dogs; D010988:Play and Playthings; D011187:Posture / Q000502:physiology*; D012919:Social Behavior; D016683:Supine Position
keywords: Domestic dogs; Eshkol-Wachman movement notation; Play fighting; Submission; Tactical maneuvering