Weaning in an Arctic wolf pack: Behavioral mechanisms

Abstract

If behavioral mechanisms controlling suckling have been shaped by parent-offspring conflict in the ultimate sense, then proximate behavioral determinants of conflict should occur throughout lactation, with greatest intensity in the terminal phase, and offspring should have tactics for overcoming parental resistance. We observed the weaning process in a habituated wild wolf pack (Canis lupus) on Ellesmere Island, Canada, from estimated ages 5 through 10 weeks (including a continuous record for 192 h). The following variables declined with age: percentage of suckling bouts initiated by the nurser, persistence by pups, and mean duration of suckling bouts. Variables that increased with age were interbout interval, percentage of suckling bouts terminated by the nurser, and wincing or agonistic actions of the nurser. Behavioral conflict appeared in the develop mental stage (estimated age 7 -8 weeks) during which pups could feed on opened carcasses. Countertactics by pups to obtain milk were not apparent, although the pups developed diverse tactics for obtaining and sharing meat. In this group of wolves, weaning mechanisms were a complex function of food-delivery by adults, discomfort of the nursing female as pups developed, and declining persistence of pups. If there is a conflict over what is optimal for pups and for the nurser in the ultimate sense, behavioral conflict is more likely to be expressed with regard to access to meat, or as conditional tactics dependent on food availability, rather than weaning conflict being controlleg by fixed rules in this species.