Male-Instigated Break-up of a Family of Black Bears

• Published in: Ursus (International Association for Bear Research and Management) 1998-01, Vol.10, p.575-578
• Main Authors: Ternent, Mark A., Garshelis, David L.
• Format: Article
• Language: English
• Subjects: Bears; Black bears; Breeding; Food availability; Mating behavior; Mothers; Observational research; Physiology, Behavior, and Evolution; Social interaction; Suckling; Yearlings
• ISSN: 1537-6176; 1938-5439

A free-ranging, human-habituated female black bear (Ursus americanus) accompanied by 3 yearling offspring was visually observed for about 100 hours (Apr-Oct) in the Camp Ripley Military Reservation, central Minnesota. During April-June, the mother played with and suckled the yearlings, although she was not lactating. The duration of suckling bouts by the yearlings was not significantly different from when they were cubs. During a suckling bout the mother was approached by a breeding-age male; she was initially aggressive toward the male, but then she turned her aggression toward the yearlings and left the area without them. These observations appear inconsistent with the theory of parent-offspring conflict, which predicts a gradual lessening of parental care rather than the abrupt, male-instigated break-up we observed. Caring for yearlings apparently exacted little cost to the mother until breeding activities began. We also observed 2 instances of yearlings rejoining for brief periods, independent of the mother and >2 months after family break-up.