Calls hold clues to a male’s paternal potential

WASHINGTON - A new study has shown that courtship calls help females penguin decide which males are likely to be devoted dads.

Penguin calls may not be music to our ears, but to penguin females they hold clues to a male’s paternal potential, author Emma Marks of the University of Auckland and colleagues reported.

To find out, Marks travelled to Antarctica’s remote Ross Island, summer home to half a million Adelie penguins.

Over the course of the next three months she weighed dozens of males and recorded their calls with a handheld microphone. She also noted how successful they were at attracting mates and raising chicks.

When the researchers examined the calls, they found that steady frequency over the longest part of the call - 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.

“The fat surrounding the male’s voice box changes what his call sounds like,” said co-author Dianne Brunton of Massey University in New Zealand.

“We don’t yet know the physiological mechanism for call production, but body fat appears to stabilize their calls,” Marks added.

By listening to male courtship calls, a female can tell how fat a male is and what kind of father he’ll be, Brunton explained.

Fatter males make better fathers because they have the energy reserves to endure long fasts, so are less likely to leave the nest and desert their chicks.

“A fat male is a good choice for a female because males do so much of the offspring care,” said Brunton.

“They’re able to incubate the eggs for longer and use up their fat stores, while skinny males aren’t able to do that.” Brunton added.

This study has been published in the journal Behaviour. (ANI)