Male bottlenose dolphins form bachelor groups with their relatives

March 05, 2019

When it comes to wooing the 'ladies', it turns out male bottle nose dolphins employ special tactics with their brothers or cousins to increase their odds of sexual success.

New research has analysed the behaviour of 12 dolphin social groups in South Australia's Coffin Bay region and shows males who team up in groups of two to five to form beneficial alliances may have more success.

The collaboration improves the bottle nose chances of finding and breeding with females in a competitive environment, ensures they stay fit, and leads to stronger family bonds over time.

Led by Dr Fernando Diaz-Aguirre at the Molecular Ecology at Flinders University, the study examined the social and genetic structure of Southern Australian dolphins dealing with population density, an unfavourable sex ratio, and their own behavioural characteristics.

"Our research shows males form tight groups likely to increase their chances at mating with limited numbers of females, and at the same time they can defend females and prevent other male groups from mating with them," says Dr Diaz-Aguirre.

"The study highlights which geographic and demographic factors directly influence how male dolphins go about increasing their success rate with females."

Male lions, chimpanzees and horses are known to form bachelor groups in the animal kingdom, but it's even more important for dolphins because females only give birth to a single calf every two to five years.

Previous research has shown other dolphin's types form similar relationships, but this study analysed why bonds are based on blood relations in the Coffin Bay region.

"The results corroborate predictions that a high density of dolphins living in an environment which presents unfavourable sex ratios are likely to result in the formation of male social groups", states Associate Professor Luciana M?ller, senior author of the study.

"In addition, the groups clearly tend to favour relationships based on blood relations. So it's very similar to a group of humans, as we obviously socialise more with our relatives, such as brothers or cousins due to family relationships and because that's who we feel more comfortable with", says Dr Diaz-Aguirre.

Photo-identification data and biopsy samples were collected in Coffin Bay from 2013 to 2015 through boat-based surveys.

Previous studies have found that male dolphins who form close alliances breed more successfully in similar circumstances.
-end-


Flinders University

Related Dolphins Articles from Brightsurf:

Study finds high levels of toxic pollutants in stranded dolphins and whales
Researchers examined toxins in tissue concentrations and pathology data from 83 stranded dolphins and whales from 2012 to 2018.

Tracking humanity's latest toxins in stranded whales and dolphins
As humanity develops new types of plastics and chemicals, researchers are constantly trying to keep up with understanding how these contaminants affect the environment and wildlife.

Young dolphins pick their friends wisely
Strategic networking is key to career success, and not just for humans.

Dolphins learn foraging skills from peers
Dolphins can learn new skills from their fellow dolphins. That's the conclusion of a new study reported in the journal Current Biology on June 25.

Dolphins learn in similar ways to great apes
Dolphins learn new foraging techniques not just from their mothers, but also from their peers, a study by the University of Zurich has found.

Shelling out for dinner -- Dolphins learn foraging skills from peers
Dolphins use empty gastropod shells to trap prey. A new study demonstrates for the first time that dolphins can learn this foraging technique outside the mother-calf bond - showing that they have a similar cultural nature to great apes.

Good night? Satellite data uncovers dolphins on the move at nighttime
More than 1,000 bottlenose dolphins live in Florida's Indian River Lagoon year-round.

Cooperative male dolphins match the tempo of each other's calls
When it comes to working together, male dolphins coordinate their behavior just like us.

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

Lights on fishing nets save turtles and dolphins
Placing lights on fishing nets reduces the chances of sea turtles and dolphins being caught by accident, new research shows.

Read More: Dolphins News and Dolphins Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.