Where we humans like to fake a headache, at least according to common clichés, the animal world has its own tricks. And they sound much more radical. When it comes to escaping unwanted male attention, some species of frogs have taken drastic measures. They seem to be deliberately faking their own death.
Corresponding research sheds new light on the European common frog: During the mating season, situations sometimes arise in which several males cling to one female, which can have a fatal outcome. Female common frogs obviously want to avoid this risk, and do so quite consciously.
“Until now, it was assumed that females were unable to decide or defend themselves against this male overpowering,” says Dr. Carolin Dittrich, one of the authors of the current study by the Natural History Museum Berlin. However, research now suggests that this may very well be the case. “Females in these dense breeding groups are not passive, as previously assumed,” says Dittrich.
For their experiments, the scientist and her colleague Mark-Oliver Rödel each placed a male frog in a box with two females: one large and one small. The mating behavior was then recorded on video. The results showed that numerous females actively tried to free themselves from the clutches, made noises of protest – or even played dead. “Tonic immobility” – a stiffening of the body with arms and legs outstretched – occurred in 33 percent of all female frogs that were clasped by a male.
The research group found that smaller females used all three tactics together more often than larger females. Incidentally, the finding is not entirely new, as Carolin Dittrich reveals: “I found a book by Rösel von Rosenhoff from 1758 in which this behavior was described,” she says – but then it was never mentioned again for more than 250 years to become. The three tactics observed would have enabled at least some females to escape the clutches of the males in the experiments.
Sources: Study, Guardian
