A new study, led by Florida Atlantic University’s Harbor Branch Oceanographic Institute, has used molecular genetic techniques and field studies to pull together decades of research into the complex relationships among beluga whales.
The research examines 10 locations across the Arctic from Alaska to Canada and Russia to Norway. This study is the first to analyse the relationship between group behaviours, group type, group dynamics, and kinship in beluga whales. The team’s findings suggest that beluga whales live in complex societies, not dissimilar to humans.
“This research will improve our understanding of why some species are social, how individuals learn from group members and how animal cultures emerge,” said Greg O’Corry-Crowe, Ph.D., lead author and a research professor at FAU’s Harbor Branch. “It also has implications for traditional explanations based on matrilineal care for a very rare life-history trait in nature, menopause, which has only been documented in a handful of mammals, including beluga whales and humans.”
Findings indicate that beluga whales regularly interact with close kin, including close maternal kin, and also frequently associate with more distantly related and unrelated individuals. Belugas likely form multi-scale societies from mother–calf dyads to entire communities.
The study has found that beluga communities have some similarities with human ones, where social networks, support structures, cooperation and cultures involve interactions between kin and non-kin. Beluga whales have a lifespan of approximately 70 years, so it is possible that they may form long-term affiliations with unrelated as well as related individuals.
Researchers found that belugas formed a limited number of group types, from mother-calf dyads to adult male groups, and from mixed-age groups to large herds. These same group types were consistently observed across population and habitats. Furthermore, certain behaviours were associated with group type, and group membership was found to often be dynamic.
“Unlike killer and pilot whales, and like some human societies, beluga whales don’t solely or even primarily interact and associate with close kin,” said O’Corry-Crowe. “Across a wide variety of habitats and among both migratory and resident populations, they form communities of individuals of all ages and both sexes that regularly number in the hundreds and possibly the thousands. It may be that their highly developed vocal communication enables them to remain in regular acoustic contact with close relatives even when not associating together.”
The research team used field observations, mtDNA profiling, and multi-locus genotyping of beluga whales to address fundamental questions about beluga group structure, and patterns of kinship and behaviour, which provide new insights into the evolution and ecology of social structure in this Arctic whale.
“Beluga whales exhibit a wide range of grouping patterns from small groups of two to 10 individuals to large herds of 2,000 or more, from apparently single sex and age-class pods to mixed-age and sex groupings, and from brief associations to multi-year affiliations,” said O’Corry-Crowe. “This variation suggests a fission–fusion society where group composition and size are context-specific, but it may also reflect a more rigid multi-level society comprised of stable social units that regularly coalesce and separate. The role kinship plays in these groupings has been largely unknown.”
The study was conducted at 10 locations, in different habitats, across the species’ range, spanning from small, resident groups (Yakutat Bay) and populations (Cook Inlet) in subarctic Alaska to larger, migratory populations in the Alaskan (Kasegaluk Lagoon, Kotzebue Sound, Norton Sound), Canadian (Cunningham Inlet, Mackenzie Delta, Husky Lakes) and Russian (Gulf of Anadyr) Arctic to a small, insular population in the Norwegian High Arctic (Svalbard).
“This new understanding of why individuals may form social groups, even with non-relatives, will hopefully promote new research on what constitutes species resilience and how species like the beluga whale can respond to emerging threats including climate change,” said O’Corry-Crowe.
To read the full study and for information regarding co-authors, “Group structures and kinship in beluga whale societies”, click here.
Video and still courtesy of FAU’s Harbor Branch Oceanographic Institute.
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