Featured Research

from universities, journals, and other organizations

Old males rule the roost even as sex drive fades

Date:
July 19, 2010
Source:
University of Oxford
Summary:
Old roosters can still dominate the sexual pecking order even when their ability to fertilize eggs drastically declines, new research has shown.

Old roosters can still dominate the sexual pecking order even when their ability to fertilize eggs drastically declines, new research has shown.
Credit: iStockphoto/Peter Zelei

Old roosters can still dominate the sexual pecking order even when their ability to fertilise eggs drastically declines, new research has shown.

Related Articles


A study of feral chickens, reported recently in Current Biology, suggests an evolutionary battle between what's good for old roosters and what's good for their hens -- which would benefit from sex with younger, more potent males.

The team, led by Oxford University researchers, studied the relationship between the status of male birds, their reproductive performance, and female reproductive success, in a feral population of chickens in Sweden.

'We found that roosters decline in a number of key reproductive traits as they age -- from libido to sperm quality -- and, in groups where there's intense competition, tend to lose out to younger males,' said Dr Tommaso Pizzari of Oxford University's Department of Zoology, an author of the report. 'However, old males remain capable of dominating the pecking order: When this happens they can monopolise access to females but, because of their sexual decline, they fail to fertilise all the eggs available. This implies an evolutionary conflict between ageing roosters and fertile hens.'

The researchers used four different experiments to separate out the influence of male and female factors on reproductive success -- something that is difficult to study in wild animals. It is only recently that scientists have started to understand the significant role that age-related 'sexual decline' (reproductive senescence) plays in natural animal populations.

'In evolution there are many battlegrounds, but nothing is more important than successfully reproducing. So, for hens, being monopolised by an impotent old rooster who will cause them to lay many infertile eggs is a disaster and amounts to a declaration of war. Our study shows that this sort of sexual decline is an engine driving sexual conflict in animals,' said Dr Rebecca Dean of Oxford University's Department of Zoology, also an author of the report.


Story Source:

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


Journal Reference:

  1. Dean et al. Male Reproductive Senescence Causes Potential for Sexual Conflict over Mating. Current Biology, 2010; 20 (13): 1192 DOI: 10.1016/j.cub.2010.04.059

Cite This Page:

University of Oxford. "Old males rule the roost even as sex drive fades." ScienceDaily. ScienceDaily, 19 July 2010. <www.sciencedaily.com/releases/2010/07/100713151315.htm>.
University of Oxford. (2010, July 19). Old males rule the roost even as sex drive fades. ScienceDaily. Retrieved January 28, 2015 from www.sciencedaily.com/releases/2010/07/100713151315.htm
University of Oxford. "Old males rule the roost even as sex drive fades." ScienceDaily. www.sciencedaily.com/releases/2010/07/100713151315.htm (accessed January 28, 2015).

Share This


More From ScienceDaily



More Mind & Brain News

Wednesday, January 28, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

City Divided: A Look at Model Schools in the TDSB

City Divided: A Look at Model Schools in the TDSB

The Toronto Star (Jan. 27, 2015) Model schools are rethinking how they engage with the community to help enhance the lives of the students and their parents. Video provided by The Toronto Star
Powered by NewsLook.com
Man Saves Pennies For 65 Years

Man Saves Pennies For 65 Years

Rooftop Comedy (Jan. 26, 2015) A man in Texas saved every penny he found for 65 years, and this week he finally cashed them in. Bank tellers at Prosperity Bank in Slaton, Texas were shocked when Ira Keys arrived at their bank with over 500 pounds of loose pennies stored in coffee cans. After more than an hour of sorting and counting, it turned out the 81 year-old was in possession of 81,600 pennies, or $816. And he&apos;s got more at home! Video provided by Rooftop Comedy
Powered by NewsLook.com
How Technology Is Ruining Snow Days For Students

How Technology Is Ruining Snow Days For Students

Newsy (Jan. 25, 2015) More schools are using online classes to keep from losing time to snow days, but it only works if students have Internet access at home. Video provided by Newsy
Powered by NewsLook.com
Weird Things Couples Do When They Lose Their Phone

Weird Things Couples Do When They Lose Their Phone

BuzzFeed (Jan. 24, 2015) Did you back it up? Do you even know how to do that? Video provided by BuzzFeed
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


Health & Medicine

Mind & Brain

Living & Well

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