title: Play in juvenile mink: litter effects, stability over time, and motivational heterogeneity.
abstract: Mink are potentially ideal for investigating the functions of play: deleterious effects of early social isolation suggest a crucial developmental role for play; and huge numbers of highly playful juvenile subjects can be studied on farms. We collected descriptive data on 186 pairs from 93 litters, half provided with play-eliciting environmental enrichment objects in their home cages, to test three hypotheses: (1) play frequency is subject to litter effects; (2) relative playfulness is stable over time; (3) play sub-types share a single, common motivational basis. We found weak litter effects that were driven by stronger litter effects on general activity, and weakly stable individual differences in both total and rough-and-tumble play. Experimentally increasing object play did not inhibit rough-and-tumble play, showing these sub-types are not motivational substitutes. Frequencies of these sub-types were also uncorrelated, and changed differently with time of day and age, further supporting this conclusion.
authors.affiliation: Department of Comparative Medicine, Stanford University, Stanford, California.|Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Jamie
authors.initials: J
authors.lastname: Ahloy Dallaire
authors.affiliation: Department of Animal Biosciences, University of Guelph, Guelph, Ontario, Canada.
authors.forename: Georgia J
authors.initials: GJ
authors.lastname: Mason
mesh_terms: D000367:Age Factors; D000818:Animals; D001522:Behavior, Animal / Q000502:physiology*; D005260:Female; D008297:Male; D008907:Mink / Q000502:physiology*; D009042:Motivation / Q000502:physiology*
keywords: American mink; animal behavior; juvenile period; motivational substitutes; object play; play; rough-and-tumble play