Dolphins gather in female family groups

FEBRUARY 10, 2020

by Flinders University

Social clusters including mothers' groups play an important role in the life of southern Australian bottlenose dolphins, a new study shows.

Similar in giraffes, lions, hyenas and grey kangaroo populations, bottlenose dolphins appear to form social bonds with kin and other females in similar reproductive condition, while maintaining moderate and loose social bonds with some same-sex individuals.

A study at a popular holiday destination in South Australia found female bottlenose dolphins (Tursiops cf. australis) raise young in select group and local bays, further highlighting the need for more protection from marine sanctuary and controls on aquaculture and fishing.

Marine biologist Dr. Fernando Diaz-Aguirre, who studies and photographs marine wildlife, has supported long-term observations of bottlenose dolphins in the Coffin Bay region of SA's Eyre Peninsula.

Just like in human communities, he says the dolphins tend to form family groups, with those females most closely related genetically forming close social relationships in specific areas of the large open Coffin Bay.

"These close social groups among related females appear to be vital for them while raising young calves, or for those without calves who also combine due to similar biological requirements related to feeding and mating," Dr. Diaz-Aguirre says.

"As well as key pointers on social evolution and behavior in these highly complex marine mammals, our study also provides important information for the conservation of the Coffin Bay population."

Depending on kinship and other ties, specific females and their young either live in Kellidie Bay, Mt Dutton or near Port Douglas—giving key clues for reducing anthropogenic threats such as boat strikes, entanglement in fishing gear, or habitat displacement due to aquaculture and pollution.

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