Featured Research

from universities, journals, and other organizations

Penguin males with steady pitch make better parents

Date:
July 12, 2010
Source:
National Evolutionary Synthesis Center (NESCent)
Summary:
Courtship calls help penguin females decide which males are likely to be devoted dads, according to a new study. By listening to male courtship calls, a female can tell how fat a male is and what kind of father he'll be. 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.

To lure a female to his nest, a male flaps his flippers, points his beak to the sky, and emits a series of loud trills and squawks.
Credit: Photo by Emma Marks

How does a female penguin choose a mate? Courtship calls help females decide which males are likely to be devoted dads, says a study in the journal Behaviour.

Related Articles


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. Adelie penguins pull it off by tag-team parenting, the researchers explained. Males and females take turns incubating the eggs and guarding the chicks while their mate forages for food.

Males arrive first to claim a territory and build a nest. When the females arrive, the males serenade prospective mates by throwing their heads back, pointing their beaks to the sky, and emitting a series of hoarse trills and squawks.

"They're not musical calls -- they sound like a cross between a donkey and a stalled car," said 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, Marks and colleagues report.

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 duty without breaking to eat. By relying on stored fat reserves, father penguins can lose more than 20% of their body weight over the course of the summer breeding season, the researchers said.

"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," she added.

The researchers wanted to know how courtship calls help a penguin female choose the father of her chicks. "We knew that females preferred some males over others. But we didn't know what traits females were using to choose a good mate," said co-author Dianne Brunton of Massey University in New Zealand.

"If she chooses a male with a particular kind of call, does she have a better chance of successfully raising chicks?" Marks asked.

To find out, Marks traveled 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.

Males with more consistent pitch were snatched up more quickly. These males were also heavier and more successful at raising chicks, the researchers found. "The fat surrounding the male's voice box changes what his call sounds like," said Brunton. "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."

The researchers also wondered if males were always honest about their potential as caring fathers, or merely bluffing to attract a mate. "What if the guy calls, and it turns out he's a skinny bird pretending to be a fat bird, making himself sound better than he really is?" said Marks.

"Females can't judge how fat a male is just by looking at him," said Brunton. "How fat he looks depends on how he's standing and how fluffed up his feathers are."

A male who lies about his paternal commitment might increase his chances of passing on his genes, said co-author Allen Rodrigo, Director of the National Evolutionary Synthesis Center in Durham, North Carolina. For that reason, females are likely to be on the lookout for the most honest indicators of paternal potential, he explained.

As penguin dads lost weight over the chick-rearing season, their calls changed too, Marks found. "So a skinny male is unlikely to be able to pretend he's a big fat male. He can't fake it," said Marks.


Story Source:

The above story is based on materials provided by National Evolutionary Synthesis Center (NESCent). Note: Materials may be edited for content and length.


Journal Reference:

  1. Emma J. Marks, Allen G. Rodrigo, Dianne H. Brunton. Ecstatic display calls of the Adιlie penguin honestly predict male condition and breeding success. Behaviour, 2010; 147 (2): 165 DOI: 10.1163/000579509X12512863752751

Cite This Page:

National Evolutionary Synthesis Center (NESCent). "Penguin males with steady pitch make better parents." ScienceDaily. ScienceDaily, 12 July 2010. <www.sciencedaily.com/releases/2010/07/100712102806.htm>.
National Evolutionary Synthesis Center (NESCent). (2010, July 12). Penguin males with steady pitch make better parents. ScienceDaily. Retrieved November 27, 2014 from www.sciencedaily.com/releases/2010/07/100712102806.htm
National Evolutionary Synthesis Center (NESCent). "Penguin males with steady pitch make better parents." ScienceDaily. www.sciencedaily.com/releases/2010/07/100712102806.htm (accessed November 27, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Thursday, November 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Dinosaur Species Found in Museum Collection

New Dinosaur Species Found in Museum Collection

Reuters - Innovations Video Online (Nov. 27, 2014) — A British palaeontologist has discovered a new species of dinosaur while studying fossils in a Canadian museum. Pentaceratops aquilonius was related to Triceratops and lived at the end of the Cretaceous Period, around 75 million years ago. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) — The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) — Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) — The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins