Featured Research

from universities, journals, and other organizations

Birds must choose between mating and migrating

Date:
April 6, 2011
Source:
University of Guelph
Summary:
Sex or nice weather. That's the agonizing choice some birds face, according to a new study. Researchers discovered that for some male birds traveling to areas with lighter rainfall comes at the cost of attracting a female when they return home.

Two adult male White-ruffed Manakins are shown here perched above their lek at Rara Avis, Costa Rica.
Credit: David Vander Plyum

Sex or nice weather. That's the agonizing choice some birds face, according to a new University of Guelph study.

A team led by Guelph researchers discovered that for some male birds traveling to areas with lighter rainfall comes at the cost of attracting a female when they return home.

Alice Boyle, a former U of G post-doc, Prof. Ryan Norris and Prof. Chris Guglielmo, a biologist at the University of Western Ontario, examined the breeding behaviour of the white-ruffed manakin. This small Costa Rican bird is partially migratory, choosing each year whether to migrate or stay.

During the heavy rainy season some Manakins will migrate to lower elevations where the lighter rainfall makes it easier to forage for food.

The researchers discovered the males that choose to stay behind may gain better breeding sites and are more likely to increase or maintain their standing within the population, making them more attractive to females.

"The manakins are faced with the choice of boosting their chances of survival or boosting their chances of breeding," said Norris, an integrative biology professor. "Most animals migrate because of the cold but in the tropics you see some populations that are partially migratory. These species provide a window into the evolution of migrating and a unique opportunity to examine the costs and benefits of this behaviour."

The study published April 6 in Biology Letters is the first to investigate costs and benefits of staying or going in a partially migratory species.

During two breeding seasons, the researchers tagged almost 200 birds to observe their status and mating success. Alpha males in the population often have the most prominent breeding sites and perform the most elaborate aerobatic displays to attract the females.

To learn which birds had migrated or not before the breeding season, the scientists tested samples of their claws. Migrating birds have more heavy hydrogen in their claws. Rain at the lower elevation contains more of these isotopes, which end up in plants and berries eaten by the manakins, said Norris.

"These isotopes of hydrogen then become fixed in their nails," he said. "The problem with studying migration is that it's hard to follow the animals around, but this method allowed us to go back in time to find out what the bird was doing before we captured it."

The researchers found that males that did not migrate had better breeding sites, a higher status and attracted more females than the migrating males.

Choosing to stay or go is likely based on a number of factors, said Boyle.

"Birds that are younger are more likely to migrate because they still have several years of breeding opportunities ahead of them," she said. "It's often the older birds with a higher status that stay not only because there is a sense of urgency to breed but also they know staying will improve their chances of becoming an alpha."

Migrating birds are often in poorer condition and less likely to survive the heavy rains, said Boyle. They also aren't next in line to becoming an alpha so they won't be losing out on the opportunity if they leave, she added.

"These factors can change from year to year which is why we see these birds choose different options each year. They have to decide what makes the most sense for them based on their status and condition."


Story Source:

The above story is based on materials provided by University of Guelph. Note: Materials may be edited for content and length.


Journal Reference:

  1. W. Alice Boyle, Christopher G. Guglielmo, Keith A. Hobson, and D. Ryan Norris. Lekking birds in a tropical forest forego sex for migration. Biology Letters, April 6, 2011 DOI: 10.1098/rsbl.2011.0115

Cite This Page:

University of Guelph. "Birds must choose between mating and migrating." ScienceDaily. ScienceDaily, 6 April 2011. <www.sciencedaily.com/releases/2011/04/110406085323.htm>.
University of Guelph. (2011, April 6). Birds must choose between mating and migrating. ScienceDaily. Retrieved September 14, 2014 from www.sciencedaily.com/releases/2011/04/110406085323.htm
University of Guelph. "Birds must choose between mating and migrating." ScienceDaily. www.sciencedaily.com/releases/2011/04/110406085323.htm (accessed September 14, 2014).

Share This



More Plants & Animals News

Sunday, September 14, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) — New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) — A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
'Magic Mushrooms' Could Help Smokers Quit

'Magic Mushrooms' Could Help Smokers Quit

Newsy (Sep. 11, 2014) — In a small study, researchers found that the majority of long-time smokers quit after taking psilocybin pills and undergoing therapy sessions. Video provided by Newsy
Powered by NewsLook.com
Spinosaurus Could Be First Semi-Aquatic Dinosaur

Spinosaurus Could Be First Semi-Aquatic Dinosaur

Newsy (Sep. 11, 2014) — New research has shown that the Spinosaurus, the largest carnivorous dinosaur, might have been just as well suited for life in the water as on land. 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:
from the past week

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