Northern Resident Killer Whale Group Cohesion (1980-2010)

Data from: Stredulinsky et al. (2021) Family feud: permanent group splitting in a highly philopatric mammal, the killer whale (Orcinus orca). Behavioural Ecology and Sociobiology. https://link.springer.com/article/10.1007/s00265-021-02992-8. Group cohesion and demographic parameters were derived from annual censuses of Northern Resident Killer Whales (NRKW) in Pacific Canadian coastal waters, conducted by DFO's Cetacean Research Program since 1973. For animals that tend to remain with their natal group rather than individually disperse, group sizes may become too large to benefit individual fitness. In such cases, group splitting (or fission) allows philopatric animals to form more optimal group sizes without sacrificing all familiar social relationships. Although permanent group splitting is observed in many mammals, it occurs relatively infrequently. Here, we use combined generalized modeling and machine learning approaches to provide a comprehensive examination of group splitting in a population of killer whales (Orcinus orca) that occurred over three decades. Fission occurred both along and across maternal lines, where animals dispersed in parallel with their closest maternal…

Publisher

Fisheries and Oceans Canada

Resources

6

Catalogue metadata updated

2026-03-24