Study: Female frogs fake their own deaths to avoid persistent males to avoid sex if they are not interested

Researchers have discovered that female frogs employ a range of strategies, including pretending to be dead, rotating, and emitting release calls, to avoid unwanted mating attempts from persistent males. These findings were published in the journal Royal Society Open Science, shedding light on the complex mating behaviors of frogs.

The study focused on the European common frog and examined the aggressive mating behaviors displayed by these frogs. Specifically, the researchers identified three distinct female avoidance behaviors: “rotation,” “release call(s),” and tonic immobility, commonly referred to as “death feigning.”

The scientists noted that these behaviors were more prevalent among smaller female frogs, and smaller individuals were more successful in evading the male frogs’ attempts to amplex them, which is the mating position for frogs and toads.

European common frogs are known as “explosive” breeders, often congregating in large numbers in ponds for mating. Males typically outnumber females, resulting in intense competition during mating.

Carolin Dittrich, a researcher at the Natural History Museum in Berlin, explained that within these mating balls, some females may face severe consequences, even death. However, females have developed various tactics to avoid mating, allowing them to exert control over their reproductive choices. These strategies are not passive but rather active ways for females to navigate their mating preferences. It may be that they are not ready to breed or do not want to mate with specific males.

To conduct the study, the researchers collected both male and female European common frogs from a breeding pond. They then divided the frogs into two tanks, each housing two females and one male. After observing the frogs for an hour, they found that 83 percent of the females employed the tactic of rolling onto their backs when grasped by a male, causing the male to let go to avoid drowning. In addition, approximately one-third of the females lay motionless with their limbs outstretched for about two minutes after being mounted by a male, suggesting a potential “playing dead” strategy. However, it remains uncertain whether this behavior is a conscious choice or an automatic response to stress.