Research finds female frogs play dead to avoid mating with males

In some species of frogs, the females play dead to avoid mating with aggressive males. Dr. Carolin Dittrich, behavior ecologist at the University of Veterinary Medicine Vienna, tells us more.

Ever felt the impulse to ghost that person who keeps hitting on you and just can't take a hint? - you know, just never talk to them again, just disappear. Frogs have taken that strategy to a new level. A new study shows that some female frogs will play dead to avoid mating.

CAROLIN DITTRICH: Usually, they are laying on the side and stretching arms and legs, like, stiffly from the body. So that's the typical position.

RASCOE: That's Dr. Carolin Dittrich. She's a behavioral ecologist at the University of Veterinary Medicine, Vienna. She observed the behavior for the first time while monitoring mating patterns.

DITTRICH: I had one male and two females in a box, and I let them be there for an hour, undisturbed. And I saw in one video that the female appeared dead, so I got a bit worried that something happened.

RASCOE: Scientists have called playing dead tonic immobility. It's one of the strategies females use to avoid mating, along with rotating their body or letting out a call to tell males they're not interested. That's because mating is brutal in the species she's studying. These frogs are known as explosively breeding frogs. They have a very short mating season. Male frogs in this species get so aggressive that the females can fear for their lives.

DITTRICH: Usually, there's more males than females in the breeding aggregation. That means that males are fighting to get access to the females. And sometimes, a lot of males can cling to one female, which leads to the drowning of the female.

RASCOE: Dittrich notes it's just a reflex for the females.

DITTRICH: It seems it's not a conscious decision of feigning death - like, I don't like this male, so I feign death or something like that - but more like a survival tactic or strategy. So the males - sometimes, they still cling to the females even if they feign death or are immobile. And sometimes, they let go.

RASCOE: Dittrich doesn't know if other species play dead to avoid mating. We've all heard of possums, but that's to avoid a predator.

DITTRICH: But I think that when species have similar selection pressures - like big breeding aggregations, more males than females, this short breeding time - I think these selection pressures could lead to the evolution of this behavior in other species, too.

RASCOE: So male frogs - when you see a female playing dead, maybe make a ribbit - or pivot - to another mate.

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