Rodent mothers produce more offspring after smelling odors produced by frightened males. This is reported by a team of biologists from Finland and the Netherlands and bring new information the proximate and ultimate explanations of small mammal behavioral responses.
Fear of being eaten has the power to shape populations and drive evolution. The effect the authors report is large: exposed mothers produce litters with about fifty percent more pups compared to unexposed control mothers.
Chemical messages
Predation involves more than just predators consuming prey.
The study shows that a frightening experience can be communicated to neighboring individuals in the population, even when the neighbors do not see, smell, or hear an actual predator themselves.
Vole mothers might produce more offspring when they sense their chances of being eaten soon are high and that their next litter may be their last. Simple physiological mechanisms could allow mothers to adjust litter size. For example, previous research has shown that females can produce more pups simply by mating with more males.
Implications of the findings
Danielle Lee of the Southern Illinois University (USA), an ecologist specializing in rodent behavior and who is unaffiliated with this research project, described the significance of this research.
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The study of wild bank voles (Myodes glareolus) in Konnevesi Research Station of the University of Jyväskylä, Finland, is published 21.11.2018 in the open access journal Scientific Reports .
Additional information:
Scientific Reports