Photo credit: Chmee2
Nature is full of sometimes hilarious phenomena. This is the case for female common frogs. Did you know that they fake death to avoid mating? How can we understand this extraordinary phenomenon? What can drive female frogs to such an extreme? We carried out the investigation among the common frog.
An unpleasant love season
In some species of frogs, the mating period is not exactly a pleasure. This is particularly for the female red frog. An article published in the journal Royal Society Open Science mentions research carried out on this subject.
According to this study, males force females to mate. To achieve this, they do not hesitate to harass, intimidate and use physical domination over females. This phenomenon is the consequence of the short space of time conducive to reproduction. This space varies from a few hours to a few weeks depending on the species. When talking about this mode of reproduction, experts use the expression “explosive reproduction”. This is particularly because this period of collective mating brings to mind intense, ferocious and frenzied orgies dictated by the pressing time.
It should also be noted that during the fertile period, male frogs outnumber female frogs. This can have fatal consequences, because the female can be attacked by several males at the same time. It therefore becomes difficult, if not impossible, to get rid of these suitors. As the scene takes place in water, the risk of death by drowning is increased for females.
Dodging maneuvers used by female frogs
The study report cited above shows that females have more than one trick up their sleeve to escape the attacks of unwanted males. The most commonly observed and used strategies by these charming ladies are: body rotation, screaming, death simulation.
The rotation of the body is a technique which aims to test the force of the evil which surrounds it while making it vulnerable to drowning. It appears that 83% of females studied use body rotation as a display when males try to mate with them.
The cry is distinguished into two distinct formats: one is a growl, while the other is a squeak. Using this subterfuge, 48% of females imitate the males’ cry. A simple tactic, but quite effective in reducing the enthusiasm of suitors.
And finally, this slightly scary tactic, the simulation of death. It consists of stiffening the limbs and simulating a state of death. A theatrical performance worthy of an award and used by 33% of females who thus obtain the expected result.
Feigning death: a ploy beyond our imagination
In the animal kingdom, this strategy is called tonic immobility and it is used by different species to deceive predators.
We were able to observe an entire colony of ants feigning death. Among amphibians, species adept at this practice include the common frog, also known as Rana temporaria, and the Waltl’s Pleurodele, the largest newt in Europe.
By simulating death, the female frog sends her male counterpart a convincing message. Indeed, the energy deployed by a male trying to pass on his genes is so precious that there is no room for waste. Taking into account the time window that the fertile season lasts, every second is precious. Feigning death is a natural reaction that responds to the stress generated by this period in younger females who do not have much sexual experience compared to their sisters. This service also aims to test the male’s endurance. All in all, although tonic immobility does not guarantee a 100% effective result, it breaks the attacks of males, even the reckless.
No species wants to suffer harassment, forced copulation or intimidation. In frogs, this can produce a negative effect and lead to the failure of the survival of the genes of both protagonists. At present, studies do not allow us to define whether this behavior of females is due to the fact that males contribute neither to the defense of resources nor to the provision of parental care. One fact is certain: faking death breaks the test of strength argument. In this case, larger males are no more likely than smaller males to mate with females who do not want them.