Navigation Links
Hanging with the boys - female Alpine marmots benefit from a bit of pre-natal testosterone
Date:12/6/2011

Alpine marmots (Marmota marmota) live in extended family groups of up to 20 individuals. The groups consist of a dominant territorial pair and a number of subordinate individuals, typically descendants of the dominant pair. Over a 14-year period, Klaus Hacklnder of the Institute of Wildlife Biology and Game Management, University of Natural Resources and Life Sciences, Vienna and Walter Arnold of the Research Institute of Wildlife Ecology (FIWI), University of Veterinary Medicine, Vienna investigated the lifetime reproductive success (typically measured by the number of offspring) of female Alpine marmots in a free-living population in Berchtesgaden National Park. Their results indicate a positive effect of male-bias in a litter on the development of a more aggressive female phenotype. This is important, as only the dominant female in a group gets to reproduce and the chance of a female's becoming dominant is greater the more aggressive she is.

To determine females position in the uterus, Hacklnder and Arnold used a non-invasive markrecapture technique: they captured, marked, released and recaptured an average of 141 marmots per year and collected data on group composition, female reproductive output and relatedness among group members. By determining the sex ratio (the proportion of males in a litter) for each sample group, the scientists were able to calculate the likelihood that female group members were located next to a male in the uterus, as in male-biased litters there is a greater chance that a female developed next to one or two males. The scientists had expected to find an increase in aggression in such females but were surprised to discover that reproductive success is not negatively affected by prenatal masculinization.

Previous studies on other species have shown an influence of position in the uterus on subsequent development. In house mice (Mus musculus), for example, being located between two males appears to make females more aggressive but less reproductively successful. However, it was unknown so far whether this is of any importance in free-living wild animals. Moreover, the results on Alpine marmots seem to show the opposite effect: the greater the male-bias in a litter, the better the chance for females to become dominant and hence reproductively successful. An exposure to higher testosterone levels during foetal development thus seems to give female marmots an edge over other females in a population. As Arnold says, "Male marmots only mate with the dominant female in a group and clearly do not mind that she is a bit 'butch' which she has to be to reach that position in the first place."


'/>"/>
Contact: Prof Walter Arnold
walter.arnold@vetmeduni.ac.at
43-148-909-15100
University of Veterinary Medicine -- Vienna
Source:Eurekalert

Related medicine news :

1. Changing the Course of Kids Health
2. ChangingHomeCare.com Launches Effort to Promote Future of Homecare
3. Savor: Mindful Eating, Mindful Life -- The Definitive Guide to Changing the Way People Eat and Live
4. Changing channels to eliminate chronic pain
5. Wrike Introduces a Game-Changing Microblogging Tool for Project Managers
6. Changing young peoples eating habits
7. Nurse educators changing the world highlighted in new book
8. Health Podcast by World-Renowned Health Educator Celebrates 100th Episode and Continues to Offer Life-Changing Advice
9. Study shows behaviors and attitudes towards oral sex are changing
10. Colorado researcher discovers mechanism for changing adult cells into stem-like cells
11. Practice-changing studies on how oncologists treat cancer to be presented at ASTRO Annual Meeting
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:5/26/2016)... ... May 26, 2016 , ... An April Gallup survey found rising ... 550 employees of Sun Health Senior Living (SHSL) may not share those ... doctor and prescription copays for the year, while holding the line on increasing their ...
(Date:5/26/2016)... ... May 26, 2016 , ... The Lung Institute ... a six-week smoking cessation class starting June 6 at their clinic in downtown Tampa. ... . , Additionally, the Lung Institute has created a free downloadable 4 Week ...
(Date:5/26/2016)... ... May 26, 2016 , ... ... Top Doc! Along with his wonderful accolades and stellar patient reviews, Dr. Batelli ... Dr. Batelli! , Dr. Eugene Batelli is a highly trained Podiatric Surgeon who ...
(Date:5/26/2016)... ... May 26, 2016 , ... A health conscious snack that doesn't ... Bar, has ignited an undeniable buzz in the protein product community by offering ... any doughnut.  These doughnuts are packed with 11 grams of protein and made from ...
(Date:5/26/2016)... York, NY (PRWEB) , ... May 26, 2016 , ... ... have lips been so central to popular cosmetic improvement efforts. Record numbers of clients ... kissers appear more prominent or pouty, says Kally Papantoniou, MD, of Advanced Dermatology ...
Breaking Medicine News(10 mins):
(Date:5/24/2016)... , May 24, 2016 ... beide primären Endpunkte und demonstriert ... in ‚ausgezeichneter plus guter , ...    ,      (Logo: http://photos.prnewswire.com/prnh/20130829/633895-a ... heute neue positive Daten von der MORA-Studie der ...
(Date:5/24/2016)... 2016 Celsion Corporation (NASDAQ: ... provided an update on its ongoing OVATION study, ... GEN-1, the Company,s DNA-based immunotherapy, with the standard ... with advanced ovarian cancer who will undergo neoadjuvant ... an IL-12 DNA plasmid vector formulated as a ...
(Date:5/24/2016)... May 24, 2016 Open Access ... Clinical Neurophysiology  Elsevier , a world-leading ... services, today announced the launch of Clinical ... journal that focuses on clinical practice issues in clinical ... clinical series, normal values and didactic reviews. It is ...
Breaking Medicine Technology: