In a groundbreaking genetic kinship study, a research team led by the Florida Atlantic University’s Harbor Branch Oceanographic Institute is the first to reveal that just like human societies, beluga whales (Delphinapterus leucas) appear to value culture and their ancestral roots and family ties. The researchers have demonstrated that related whales returned to the same locations year after year, and decade after decade. Not only do these whales know where to go and where not to go, they are passing on this information from one generation to the next.
Incredibly sophisticated series of vocal repertoires and acoustic systems of beluga whales (Delphinapterus leucas) suggest that they are capable of forming very complex relationships and groups. Image credit: Lisa Barry, NOAA / NMFS / AFSC / MML.
The beluga whale, also known as the white whale, beluga, melonhead, or sea canary, is a mid-sized cetacean of Arctic and sub-Arctic waters.
This species is one of two members of the cetacean family Monodontidae, along with the narwhal, and is the only member of the genus Delphinapterus.
Beluga whales spend their winters and summers in different locations where they feed, breed, molt and raise their young. Some even travel as far as 3,730 miles (6,000 km) each year.
These highly sociable animals often like to hang out in the thousands near shore during the summer when the ice melts — a whale’s version of an ‘icebreaker.’
Their incredibly sophisticated series of vocal repertoires and acoustic systems suggest that they are capable of forming very complex relationships and groups.
However, the issue of whether these animals and other non-primates are capable of developing culture has been debated for a long time partly because of how culture is defined and since they are very difficult to study in the wild.
“What intrigued us most was whether particular whales returned to where they were born or grew up and if this was an inherited behavior,” said lead author Professor Greg O’Corry-Crowe, from the Florida Atlantic University’s Harbor Branch Oceanographic Institute.
“The only way that we could definitively answer these questions was to find and track close relatives from one year to the next and one decade to the next.”
Prior to this new study, culturally inherited migration routes and destinations were inferred from studies of genetic differences between groups and populations of whales, where differences in the pattern of maternally inherited mitochondrial DNA suggested strong fidelity to an individual’s group and/or place of birth. Until now, direct evidence for such philopatry was sparse.
The study involved whales from all major coastal concentration areas in the north Pacific in three geographic areas: Gulf of Alaska, the Bering-Chukchi-Beaufort Seas, and the Sea of Okhotsk.
Professor O’Corry-Crowe and co-authors used a much expanded sample and genetic marker set comprising 1,647 whales, spanning more than three decades (1978-2010) and encompassing all major coastal summering aggregations in these geographic areas.
They analyzed 1,444 samples for both mitochondrial DNA and eight microsatellite loci and further analyzed 203 Far East whales from the literature.
Closely related whales were found to aggregate together at coastal summering areas each year, and close kin were documented at the same summering sites up to twenty years apart.
The scientists also found clear evidence of sex-biased dispersal than previous studies have shown, and documented stability in migration and dispersal behavior over ecological timeframes with notable exceptions.
“Beluga whales’ social learning, kinship, and traditional use of areas will provide scientists and population managers with a better idea of how this species perceives its environment and how they are going to respond to changes in it,” Professor O-Corry-Crowe said.
“The findings are expanding our understanding of how sophisticated non-primate societies can be and how important culture is for the survival of these species.”
“The results also will influence our thinking in terms of how populations and species are going to adapt to dramatic environmental changes. There are few places where this is more urgent than in the rapidly changing polar regions.”
The study was published online in the journal PLoS ONE.
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G. O’Corry-Crowe et al. 2018. Migratory culture, population structure and stock identity in North Pacific beluga whales (Delphinapterus leucas). PLoS ONE 13 (3): e0194201; doi: 10.1371/journal.pone.0194201
