Beluga whales form complex social networks like humans
A new study from Florida Atlantic University has revealed that beluga whales form complex social networks that extend beyond family members. Using a combination of genetic tests and field studies, the researchers discovered that beluga whales not only interact with close relatives on a regular basis, but also with distant relatives and unrelated individuals.
The study is the first to analyze the dynamics of the relationships within groups of beluga whales, drawing from decades of research.
The findings indicate that beluga communities resemble human societies in which social networks and support structures involve interactions between relatives and non-relatives. Furthermore, given their long lifespans of about 70 years, the relationships among belugas are likely to be long-term.
“This research will improve our understanding of why some species are social, how individuals learn from group members and how animal cultures emerge,” explained study lead author Dr. Greg O’Corry-Crowe.
“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.”
The comprehensive study showed that belugas form a limited number of group types that were consistent across sites in Arctic populations from Alaska to Canada and Russia to Norway. The group types observed include mother-calf dyads, adult male groups, mixed-age groups, and large herds. Like humans, there were certain behaviors associated with group type, and group membership was often 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. 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,” said Dr. O’Corry-Crowe.
“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.”
Contrary to previous assumptions, Beluga whale groups were not found to be centered around maternal or closely related females. DNA evidence showed that both smaller social groups and large herds included multiple maternal lines. In addition, many of the genetic links within a group involved paternal relatives instead of maternal relatives.
“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 Dr. 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 is published in the journal Scientific Reports.