Among many species, breeding preferences and tactics can differ among males and females. When aggressive behavior by males toward unreceptive females goes awry, it may result in failure to reproduce, and in some cases, fatality for the females involved. This may be particularly true among species of explosive breeders in anurans, an order including some 4,500 species of frogs and toads, in which a higher risk of mortality has been reported for mating females.
Among many species, breeding preferences and tactics can differ among males and females. When aggressive behavior by males toward unreceptive females goes awry, it may result in failure to reproduce, and in some cases, fatality for the females involved. This may be particularly true among species of explosive breeders in anurans, an order including some 4,500 species of frogs and toads, in which a higher risk of mortality has been reported for mating females.
Explosive breeding species—which include the European common frog, Rana temporaria—have a short and concentrated reproductive season, which is marked by intense competition among males. In contrast, prolonged breeders reproduce over longer periods, with males typically establishing separate territories—which they defend against other males—and using mating calls to attract females.
In R. temporaria, previous findings have been mixed on whether unreceptive females are able to fend off unwanted male advances. Such advances can include harassment, intimidation, and forced copulation (amplexus) by one or more males at once. At least one recent study on this topic indicates that females lack the means to guard against this aggression and characterizes their reproductive behavior as passive, but older research describes it to the contrary.
During their earlier study on mate choice among breeding R. temporaria males, the researchers used video to record the frogs’ mating behavior. Their descriptions and quantifications of the female avoidance tactics they observed led to this new work.
