Male mammals respond to a risk of sperm competition conveyed by odors of conspecific males
Article Abstract:
Sperm competition occurs when a female copulates with two or more males and the sperm of those males compete within the female's reproductive tract to fertilize her eggs. It is shown that male meadow voles, Microtus pennsylvanicus, increase their sperm investment when they mate in the presence of another male's odors. Such an increase in sperm investment does not occur by augmenting the frequency of ejaculations, but by increasing the amount of sperm in a similar number of ejaculations.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2004
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Feather-pecking and victim pigmentation
Article Abstract:
An investigation on whether there could be a genetic basis for a chicken becoming a target of feather-pecking is presented to analyze the variance in feather damage due to feather-pecking suffered by individual birds for methods. The findings illustrate that the importance of a victim's phenotype in the evolution of spiteful behaviors such as feather-pecking and have crucial implications for the welfare of domestic species.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2004
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Sophisticated sperm allocation in male fowl
Article Abstract:
Research indicates that when female fowls are sexually promiscuous, males compete for fertilizing the eggs and behave in a status-dependent sperm investment in females depending on the level of female promiscuity. Data suggest that males progressively reduce their sperm investment and preferentially save sperm to females with sexual ornaments.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2003
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