The Beluga whales are a mixture of related and unrelated individuals, like social networking humans. To such conclusion the researchers who studied belugas in ten points across the Arctic. Previously it was believed that white whales live in communities built around relatives, related through the maternal line, but new evidence contrary to this view, it is noted in Scientific Reports.
Some large whales, such as killer whales (Orcinus orca) and sperm whales (Physeter macrocephalus), social ties are built mostly within groups whose members have each other’s relatives on the maternal side. For a long time, similar to the structure of the relationship were also attributed to other, less studied species, but simply evidence that was not.
A team of researchers led by Greg O ‘Corry-with Krovom (Greg O’ Corry-Crowe) from Florida Atlantic University decided to clarify how the built and social communication in Beluga whales (Delphinapterus leucas) — toothed whales of the family naranovich (Monodontidae), which are common in Arctic waters. These animals are very gregarious and can form groups of different sizes (from ten to two thousand individuals), the degree of relationship in which is unclear.
The researchers conducted field observations of Beluga whales on the ten areas in Canada, Alaska, Chukotka, and Svalbard. Environmental conditions each of them differ, which affects the habits of these whales, for example, in some regions they formed small settled groups, and others have huge migratory flocks. To find out how strong the Beluga family ties, the authors used the analysis of mitochondrial and nuclear DNA.
The analysis showed that all the communities of Beluga whales can be divided into seven regularly occurring types. Among them was a group consisting of: mother and baby; several adults with young; immature birds; adults; individuals of all ages. Two types of groups included more than 50 individuals: they could consist of either only adult Beluga whales, or whales of different ages. Such a large community, the authors called herds. Interestingly, in groups and herds, attended by just adults, they all, with rare exceptions, were males.
Analysis of mitochondrial DNA showed that even a small group of Beluga whales consist of individuals who are descended from different mothers. In communities numbering less than 50 animals could be descendants from one to four females, and in herds, this number ranged from three to twelve. In General, most groups of belugas were a mixture of close and distant relatives and completely unrelated individuals. In large herds the proportion of the latter was higher.
Thus, contrary to the traditional prestavleniem, communities, belugas are not formed around the females and their offspring of different ages. The authors compare them with human social networks, where you interact as relatives and friends.
Social connections are important for most cetaceans. For example, the Indian bottlenose dolphins (Tursiops aduncus) that inhabit the coast of Australia, learning to hunt fish with friends who do not have relatives: dolphins chase prey into a large shell, and then remove them from there.
Sergey Knee High