Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sophisticated sexual behavior in roosters

10.11.2003



In the animal world, it’s common for females to mate with several males during one and the same reproductive period. This leads to sperm competition, that is, sperm from several different males compete to fertilize the egg at the same time.

The most common response to increased sperm competition is for males to increase the number of sperm cells to inseminate a female with. Since males’ sperm reserves are not unlimited, males should be economical in using their sperm resources. Therefore, a male should take three factors into consideration in mating: a) the female’s degree of promiscuity, that is, how many males he is competing with, b) the amount of sperm he has already invested in the female, and c) the reproductive value of the female. It is unknown how males adapt their sperm investments in relation to this set of factors.

A research team from Sweden and England have chosen to study this in chickens (Gallus gallus) at Tovetorp Zoological Research Station, Department of Zoology, Stockholm University. Chickens are highly suited to such a study since they are promiscuous, and the social status of roosters influences their access to mates.



Their study shows for the first time that roosters demonstrate a unique flexibility when it comes to allocating their sperm resources. First, roosters evince a status-dependent sperm investment that takes into consideration the female’s degree of promiscuity; second, roosters reduce the number of inseminated sperm cells in repeated mating with the same female, but increase it again when they gain access to a new female (the so-called Coolidge effect); and third, roosters prefer to mate with females of higher reproductive value. The results indicate that female promiscuity is a decisive factor in understanding the evolution of sophisticated male sexual behaviors.

Agneta Paulsson | alfa
Further information:
http://www.su.se

More articles from Life Sciences:

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Solar Collectors from Ultra-High Performance Concrete Combine Energy Efficiency and Aesthetics

16.01.2017 | Trade Fair News

3D scans for the automotive industry

16.01.2017 | Automotive Engineering

Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs

16.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>