Courtship calls hold key to good parenting among penguins

SYDNEY - How does a female penguin choose a mate? She decides whether the male is likely to be a devoted dad!

Courtship calls help females decide which males are likely to be devoted dads. Males arrive first to claim a territory and build a nest. They serenade prospective mates by throwing their heads back, pointing their beaks to the sky, emitting a series of hoarse sounds, reports the journal Behaviour.

“They’re not musical calls - they sound like a cross between a donkey and a stalled car,” said study author Emma Marks of the University of Auckland.

Penguin calls may not be music to our ears, but to penguin females they hold clues to a male’s paternal potential, said Marks and colleagues.

Antarctic penguins come on land for just a few short months each summer to breed and raise their chicks.

Raising a family in the coldest place on earth is no small feat. Penguins pull it off by tag-team parenting, the researchers explained.

After choosing a mate the female lays two eggs and returns to sea, leaving the male alone to tend the egg until she returns to take the next shift.

For the first two weeks, penguin dads do the bulk of babysitting without breaking to eat, said an University of Auckland release.

By relying on stored fat reserves, father penguins can lose more than 20 percent of their body weight over the summer breeding season. “It’s a pretty arduous task, especially for the males,” said Marks.

“If a male doesn’t have enough fat to last these fasts, he may have to abandon the eggs and go to sea before the female can make it back. So it’s imperative that the female pick a male in good condition,” Marks added.

“We didn’t know what traits females were using to choose a good mate,” said study co-author Dianne Brunton from Massey University, New Zealand.

Accordingly, Marks travelled to Antarctica’s remote Ross Island, summer home to half a million Adelie penguins, a common species, to find answers.

When researchers examined the calls, they found that an extended chattering in the middle of the male’s display, best predicts male buffness and breeding success.

“It’s as if females are listening to the stability of the call,” said Marks.