wildlife
Female grass frogs escape from males by playing dead
Mating scene in common frogs: Sometimes many males cling to a female. The researchers refer to this as a “mating ball,” which is often fatal for females. photo
© Carolin Dittrich/MfN/dpa
An animal playing dead can usually occur when dangerous predators are involved. According to a study, female grass frogs use the survival strategy differently: against males.
According to a Berlin study, female grass frogs show various defense strategies in order to avoid the numerous males willing to mate. What was particularly astonishing was the observation that the female animals sometimes play dead, as the Museum für Naturkunde Berlin reported on a current study by their researchers Carolin Dittrich and Mark-Oliver Rödel.
Sometimes fatal for females
For these frogs, breeding is limited to a few days to two weeks in spring, as the Natural History Museum explains. According to researchers, large numbers of animals gather at the pond, with males being in the vast majority and competing for the rarer females.
“The males are not picky and grab everything that moves with great force,” it said. Until now, it was assumed that the females “cannot defend themselves against coercion by the males.” Sometimes many males would cling to a female. The researchers refer to this as a “mating ball,” which is often fatal for females.
Protection from the mating ball
However, the tactics observed showed that the females in these situations were not as passive and helpless as previously thought. Playing dead could probably help stressed females protect themselves from a potentially fatal mating ball. Turning away could also be an attempt to test the strength and endurance of partners, the author duo reports in the study. Striking: According to the study, small females used all three strategies more often than larger counterparts and had a higher probability of escaping. The study was published in the journal “Royal Society Open Science”.
In a statement, Dittrich described the act of playing dead in connection with the mating as “extraordinary”. “It is generally assumed that this strategy is used last to avoid being eaten by predators.”