Thursday, November 3, 2011

Dolphins Team Up to Get the Girl

I've been following wild dolphin research for years, and I remember feeling like my world had been rocked the first time I realized Shark Bay's male dolphins formed alliances to team up and get the girl--many times without any of the tenderness or affection we often associate with them. This article from Discovery News confirms what scientists have been saying for years: The importance of a good wingman can never be underestimated.

Photo Courtesy of Wiki Commons
Dolphins Team Up To Get the Girl
Male dolphins who formed an alliance of wingmen fathered more babies than those who worked the seas solo.
Wed Nov 2, 2011 11:57 AM ET
Content provided by
ABC Science

An alliance of four male dolphins, dubbed The Beatles have shown that when blokes co-operate, they have more sexual success.

The research by a team at Macquarie University is published in the Journal of Animal Ecology. The study found that male dolphins who form an alliance fathered far more babies than those who worked in smaller groups or alone.

The researchers studied a population of 70 male and 64 female Indo-Pacific bottlenose dolphins living in Port Stephens, New South Wales. They collected skin samples from males and calves and looked for genetic markers which would reveal the paternity of the calves.

They found that 14 different males had sired 32 calves. However, nearly half of the calves -- 13 individuals -- were sired by a single alliance of four dolphins known as The Beatles.

Three calves were sired by a three-male alliance and five calves were sired by another three-male alliance.

The remaining 11 calves sired by pairs or lone males.

Males are known to form alliances in a number of species, including lions, chimpanzees, horses and, some would argue, humans.

"But there has not been any evidence to show why an alliance might be preferable," says co-author Dr Jo Wiszniewski.

"This research shows that male dolphins need to cooperate with each other to maximise their reproductive success."

Up to 80 per cent of males form alliances to seek out and reproduce with females during the spring/summer breeding season, says Wiszniewski.

"Males in alliances have better control of the females - we often see the males swimming around the females one on each side, sometimes one at the back. The female can't get away from them," she says.

"They basically herd the female - they try to keep her away from other males. They would swim by her and when she was feeding, they would feed too."

"These kind of herding events can last just from a few hours up to a few weeks at a time," says Wiszniewski.

Female dolphins only have a calf every two to five years, so in any particular year there are very few females available and ready to mate with.

"That's why there's so much pressure for males to form alliances, to become more competitive," she says.

Previous research from Western Australia also found that male dolphins who form alliances breed more successfully. But in this case, forming cooperative alliances was less surprising, Wiszniewski says, because those dolphins were related.

"If one of those males helps another reproduce, he still gets benefits because his genes still get passed on," she says.

But in Port Stephens, the cooperating dolphins weren't related.

"That's what's so fascinating. By helping another male, they are actually risking the chance that they won't reproduce with a female. So they really need a high level of cooperation and trust so then the male knows that by helping another male, he's also going to get helped."

Wiszniewski points out that one of The Beatles - John - doesn't seem to have fathered any calves.

"We have a feeling he was not a full part of the alliance. He was what we call the odd male out -- he wasn't really 'in' with the group."


Ruth Cooke said...

Interesting study, but...

Here`s the problem with this research and its conclusions:

4 males sired 13 of the calves: 3.25 calves per male. (Or 4.33, and count poor John as a zero)

3 males sired 3 calves: 1 calf per male.

3 males sired 5 calves: 1.67 calves per male.

The remaining 11 calves were sired by the other four males, who did not work as a group: 2.75 calves per male.

Obviously `The Beatles` were far more successful than the others, again, excepting poor John, who might have done better going solo. However, overall, the 10 males working in groups sired 21 calves, or only 2.1 calves per male.

In other words, unless you`re a member of the fab four, your chances of mating while part of a group were *smaller* than if you were a loner.

The researchers need to take a step back from this study, and be honest about saying, Our sample size wasn`t large enough to make any real conclusions, and further research is needed.

LisaAnn said...

Have you read the full study? Here it is in its entirety:

"Male reproductive success increases with alliance size in Indo-Pacific bottlenose dolphins (Tursiops aduncus):"

Here's another, similar article from The Royal Society:

"Complex social structure, alliance stability
and mating access in a bottlenose dolphin

And one more, from researchers at the University of Otago and Dalhousie University:

"Why Are Male Social Relationships Complex in the Doubtful Sound Bottlenose Dolphin Population?:"

Ruth Cooke said...

LisaAnn, the first link didn't work for me--I think you need a subscription or something.

The second I'm reading now, and I'll get to the third. (Yeah, I'm a bit of a science geek, too... :) )

Thanks for the links.

Girl Parker said...

This was a really interesting article. Thanks!

LTM said...

this is just really cool! I have to confess, I'm not really even sure what it means when it comes to dolphins. So like... the other dolphins help one "get to know" the girls?

Regardless, I'll be fwding this to hubs. He was a wingman on many occasions. ;p <3

Dinda Amanda said...

Banned complain !! Complaining only causes life and mind become more severe. Enjoy the rhythm of the problems faced. No matter ga life, not a problem not learn, so enjoy it :)

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