Navigation Links
Study shows costs and benefits of testosterone in birds
Date:5/13/2010

Do nice guys finish last, or will the meek inherit the earth? A new study published in The American Naturalist suggests that, at least for birds, the right answer is somewhere in between.

Individual male birds can differ dramatically in their behavior, and this difference is often due in part to how much testosterone they produce. In many species, some males produce high testosterone and are more aggressive, while others produce lower levels and are more parental.

Testosterone and the behaviors it mediates may predict how well a male succeeds. For example, an aggressive male may be more likely to obtain high-quality territories that attract females. At the same time, aggression might pose a survival risk, because aggressive males might be more likely to engage in costly fights. These considerations suggest that hormones like testosterone might be under strong natural selection in the wild.

To test this idea, a team of researchers from Indiana University studied a common songbird, the dark-eyed junco in the Appalachian Mountains of Virginia. They tested how much testosterone a male could produce by using an injection of a hormone produced in the brain that causes the bird to increase its testosterone levels temporarily, mimicking what they do naturally when fighting with other males. The researchers then followed the birds, measuring their survival and success at reproduction, both in their own nest and those of their neighbors.

They found strong relationships between testosterone and both reproduction and survival, demonstrating that natural selection is currently acting on testosterone production in this population of juncos. The exact pattern of selection they found was surprising, however. "The males that did the best at both survival and reproduction had testosterone production very close to average," said Joel McGlothlin, the lead author of the study who is now a postdoctoral fellow at the University of Virginia.
'/>"/>

Contact: Kevin Stacey
kstacey@press.uchicago.edu
773-834-0386
University of Chicago Press Journals
Source:Eurekalert

Page: 1 2

Related medicine news :

1. Study finds rotavirus vaccine greatly reduces hospitalizations for acute gastroenteritis in children
2. Childhood psychological problems create long-term economic losses, study finds
3. HIRC Research Alert: New Study Identifies Best Pharmaceutical Company Account Managers and Program Offerings
4. Study demonstrates art therapys effectiveness in pediatric asthma
5. Brain Cell Study Explains Eureka Moment
6. Study Challenges Key Autism Theory
7. New study suggests sickle cell disease may affect brain function in adults
8. Once-A-Year Vitamin D Megadose Ups Fracture Risk: Study
9. Genetic Variants Tied to MS, Study Finds
10. UT Southwestern participates in nationwide study offering free lung tumor genetic testing
11. Study finds post-transplant patients off steroids have fewer cardiovascular events
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/22/2015)... 20 years, Dr. David Cruz of Cruz Chiropractic Care ... about every type of injury that can result from car accidents ... years, the team at Doctors on Liens has been ... With the combined breadth of experience between the two, ...
(Date:1/22/2015)... 22, 2015 Yesterday, Senator Holly ... and Kristin Olsen (R-Modesto) were honored by the ... advancing biotechnology, biomedical science, medical device and pharmaceutical ... received the “2014 Life Sciences Champion” award from ...
(Date:1/22/2015)... Payday lending practices in four southern states worsen ... to the states that permit them, according to a ... Race and Wealth. , While they generate hundreds of ... the same time substantially depress economic activity, according to ...
(Date:1/22/2015)... Compare-autoinsurance.org has released a new blog post presenting a ... insurance policy . , Some types of vehicles cannot be ... newly released blog post to see if their vehicle qualifies for ... are some of the cars that cannot be covered by a ...
(Date:12/26/2014)... TX (PRWEB) December 26, 2014 The US ... in this report. In 2013, GlobalData’s forecast estimates that sales ... largest CRC market due to the high incidence of the ... with the 5EU, Japan, and China. Increased sales of CRC ...
Breaking Medicine News(10 mins):Health News:Industry Leading Chiropractor in Oceanside Joins the Doctors on Liens Network 2Health News:California Biomedical Community Honors Senator Holly Mitchell, Assemblymembers Susan Bonilla & Kristin Olsen 2Health News:California Biomedical Community Honors Senator Holly Mitchell, Assemblymembers Susan Bonilla & Kristin Olsen 3Health News:Howard University Spotlights the Economic Impact of Payday Lending in Southern States 2Health News:Some Vehicles Cannot Be Covered By An Auto Insurance Policy! 2Health News:US Colorectal Cancer Drug Market Analysis and Forecast to 2023 Report Available at ReportsnReports.com 2Health News:US Colorectal Cancer Drug Market Analysis and Forecast to 2023 Report Available at ReportsnReports.com 3Health News:US Colorectal Cancer Drug Market Analysis and Forecast to 2023 Report Available at ReportsnReports.com 4
... delivers immediate cost savings for http://www.lle-inc.com/link.html [24-hour telephone ... or seeking multilingual solutions. , ... ... LLE® http://www.lle-inc.com/index.html [(Language Learning Enterprises, Inc.)], a leading ...
... firm represents Pickerington man who contracted E. coli from ground beef ... ... (Lexis Nexis) July 25, 2008 -- http://www.donaheyohioinjurylawyers.com [The Donahey ... central Ohio, has filed a product liability lawsuit in Franklin County ...
... Colo., July 24 An Arapahoe County District,Court ... likely,amount to more than $1 million in damages ... of Inverness-based Verex, Inc., a public,company, and a ... found that PR Pharmaceuticals and its President, Steven ...
... Pa., July 24 HTH Worldwide, a global ... will begin offering its,CityHealth(R) Profiles to Living Abroad.com ... fact-filled online guides to trusted,medical care in hundreds ... tools and destination-driven information for those living,overseas or ...
... the commonest cause of blindness in the western ... the immune system influence the risk of contracting ... working in co-operation with researchers from Gttingen, Regensburg ... time, demonstrated that in cases of senile blindness ...
... sports,chiropractor, Dr. Camille Reagan to serve as a member ... Beijing. Dr. Reagan has extensive,experience in the international sports ... 2007 Pan American Games in Rio de Janeiro., ... an international sports,platform," said Dr. Reagan. "The athletes believe ...
Cached Medicine News:Health News:LLE Launches Over-the-Phone Interpretation OPI Easy Switch Program 2Health News:LLE Launches Over-the-Phone Interpretation OPI Easy Switch Program 3Health News:Donahey Law Firm Files E. Coli Product Liability Lawsuit Against Kroger Company in Franklin County Court 2Health News:Jury Award to Englewood Company to Total More Than $1 Million for Breach of Fiduciary Duties in Shareholder Class Action Case 2Health News:HTH Worldwide to Provide International Health Guide to Living Abroad.com 2Health News:Hyperactive immune resistance brings blindness in old age 2Health News:Colombia Appoints Dallas Chiropractor to Olympic Team 2
(Date:1/23/2015)... , Jan. 23, 2015  Now available for sale, The ... support that prevents ankle sprains by cushioning the ankle ... fits securely around the outside of any shoe type ... comfort while still offering protection against sprains. With customers ...
(Date:1/23/2015)... N.Y. , Jan. 23, 2015  Lixte Biotechnology Holdings, Inc. ... its Phase I trial of Lixte,s lead compound, LB‑100, is ... John S. Kovach , M.D., the founder ... planned to be completed at a single site. Accrual of ...
(Date:1/23/2015)... 2015   Leatt Corporation  (OTCQB: LEAT), a global developer, ... forms of sports, including extreme motor sports, and whose ... that the UISP Lega Motociclismo Lombardia, an Italian motocross ... wear a neck brace during its racing competitions.  ...
Breaking Medicine Technology:The Armor1 Ankle Roll Guard is the New Breakthrough Solution for Ankle Sprain Prevention! 2Lixte Biotechnology Holdings Announces Expansion Of Clinical Sites For Its Phase I Trial Of Its Lead Anti-Cancer Compound, LB-100 2Lixte Biotechnology Holdings Announces Expansion Of Clinical Sites For Its Phase I Trial Of Its Lead Anti-Cancer Compound, LB-100 3Leatt Announces Neck Braces Now Required For Motocross/Minicross Racing In Italy 2Leatt Announces Neck Braces Now Required For Motocross/Minicross Racing In Italy 3
... an international generic pharmaceuticals company, today announced that it ... Administration to market Valacyclovir Hydrochloride Tablets.     ... generic equivalent of Valtrex® by GlaxoSmithKline, had US sales ... December 31, 2010, according to IMS Health.     ...
... 2011 Amgen (Nasdaq: AMGN ) today ... and fifth years of Prolia® (denosumab) treatment, postmenopausal women ... year-over-year increases in lumbar spine and total hip bone ... The overall adverse event profile was similar for the ...
Cached Medicine Technology:Actavis Receives Approval of Valacyclovir Hydrochloride Tablets in the U.S. 2Prolia® (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial 2Prolia® (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial 3Prolia® (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial 4Prolia® (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial 5Prolia® (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial 6Prolia® (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial 7Prolia® (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial 8Prolia® (denosumab) Open-Label Extension Trial Showed Continued Increase in Bone Mineral Density Over Five Years of Treatment With Similar Safety Profile Observed in Pivotal Trial 9
... ARUP Laboratories is a national reference ... laboratory research and development. ARUP offers an ... unique medical tests in clinical and anatomic ... ARUP Laboratories' clients include more than half ...
... Laboratories is a national reference laboratory and ... and development. ARUP offers an extensive test ... tests in clinical and anatomic pathology. Owned ... clients include more than half of the ...
... ARUP Laboratories is a national reference ... laboratory research and development. ARUP offers an ... unique medical tests in clinical and anatomic ... ARUP Laboratories' clients include more than half ...
... ARUP Laboratories is a national reference ... laboratory research and development. ARUP offers an ... unique medical tests in clinical and anatomic ... ARUP Laboratories' clients include more than half ...
Medicine Products: