This data was obtained by the specialists of the Institute of Animal Taxonomy and Ecology, Siberian Branch, Russian Academy of Sciences, who have been studying behavior of different rodent species for years. In this case, they dealt with water voles (Arvicola terrestis) and several lines of house mice.
Males’ aggressiveness is inevitable as they compete for a female. The most peaceful male would get nothing. However, is the most fierce one always a winner? To answer this question, the Novosibirsk researchers sorted out the males by their aggressiveness. To this end, the males were placed together, and the researchers counted the average number of aggressive acts in correlation to the total number of social interactions. Based on the observation results, the males were divided into four groups: low-aggressive, average aggressive, aggressive and highly aggressive ones. Then the researchers checked how attractive the males from each group are to the opposite sex. When choosing marriage partners, rodents are guided by the smell. It is by the smell that they determine physical state of the candidates and their genetic peculiarities. In the course of the experiment, a female was offered samples of bedding from different males – the selected male was considered the one whose bedding the female had studied for the longest time. Aggressive (but not highly aggressive!) males turned out to be attractive to females. Representatives of other classes are less popular. Low-aggressive partners are almost of no interest to anyone, but the most fierce males turned out to be at the bottom of the preference list.
In evolutionary perspective, females’ choice is fully justified. Both low-aggressive and very aggressive males are low-polytocous, and this is because they do not know how to behave with a “lady”. For example, a water vole female needs to be prepared for coupling. A normal aggressive male and its female-friend usually come to consent within two weeks of joint keeping. And the males whose aggressiveness differs from the optimal level to any direction succeed much more seldom.
The actual prolificacy of mice depends undoubtedly on the male’s aggressiveness. With very aggressive fathers, babies die both before and after the birth. Some babies are devoured by fierce fathers. Besides, the male’s aggressiveness towards a female negatively impacts the female’s own maternal qualities and reduces actual prolificacy. If the male often bites the female, the female is not that attentive to her young. The more biting the father is, the less attentive the mother would be. It is interesting to note that other aggressive actions do not impact the maternal behaviour. By attacking or striking with a tail, the males demostrate their high social status or that they are “cool”, and the females even like that, but not biting.
The researchers came to the conclusion that the male’s aggressiveness degree is the main criterion the mice females are guided by when selecting a partner for coupling. The most attractive are the males of some optimal level of aggressiveness. It is them that possess the required parental properties, which are exceptionally important to babies’ survival. Sluggish and especially fierce males are bad husbands and fathers. That is why females almost do not select them, they almost do not have posterity, and their genes gradually disappear from the population, which maintains in that way a permanent level of aggressiveness of its members.
Nadezda Markina | alfa
The big clean up after stress
25.05.2018 | Julius-Maximilians-Universität Würzburg
Complementing conventional antibiotics
24.05.2018 | Goethe-Universität Frankfurt am Main
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
24.05.2018 | Ecology, The Environment and Conservation
24.05.2018 | Medical Engineering
24.05.2018 | Physics and Astronomy