Fakery is seen throughout the animal kingdom and is especially evident in the realm of mate selection and mating behavior. A puzzling behavior frequently observed in many species is copulation between males and females without the delivery of semen. In a world where reproduction is key to a species, survival, such behavior poses a real mystery. In a study that sheds new light on the evolution of sexual behavior, researchers have utilized a novel technique to reveal that in feral chickens, the simple stimulus generated by male mounting--in the absence of actual insemination--reduces the sexual promiscuity of a hen, indicating that even copulations that do not result in semen transfer may be crucial to defend the paternity of a male.
Females of many species often copulate with multiple males, leading to the phenomenon of sperm competition--the competition between the ejaculates of different males to successfully fertilize eggs. The battles of sperm competition occur at the cellular and molecular levels and involve the production of sperm-associated substances that boost the competitiveness of a males sperm; however, the production of these substances comes at an energetic cost to males. Males who can avoid such costs--and still successfully mate--may be at a reproductive advantage. Therefore, in some species, males may avoid sperm competition by preventing females from mating with other males. However, previous studies have not fully considered the possibility that female promiscuity may be inhibited by stimuli generated by the simple act of male mounting.
In the new study, a team of researchers led by Dr. Tommaso Pizzari of the University of Oxford tested this idea in the feral chicken, a sexually promiscuous species. By using a novel but technologically simple technique--fitting some hens with a light plastic harness covering their cloaca and thus preventing insemination--the researchers were able to separate the effect of insemination products from that of mounting alone and to detect the behavioral response of hens. The use of this technique demonstrated that mounting alone (independently of insemination) not only drastically inhibits the propensity of a hen to mate with a new rooster but also reduces the number of sperm that she obtains from a new rooster in the 2–4 days following mounting.
Heidi Hardman | EurekAlert!
Immune Defense Without Collateral Damage
23.01.2017 | Universität Basel
The interactome of infected neural cells reveals new therapeutic targets for Zika
23.01.2017 | D'Or Institute for Research and Education
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering