Grab fast and hang on for hours. A fierce grip is all the courtship finesse a male frog needs in species that reproduce in frenzied mobs.
With hundreds of Europe’s Rana temporaria frogs gathering at a natural pool, “it can look quite like a mess,” says Dittrich, now at the University of Veterinary Medicine Vienna. And dangerous. Females can drown.
Two, three or more males can clamp onto the same female, creating a tight tangle of frogs called a mating ball. Frogs don’t do internal fertilization, so males hold tight and squirm for a good position for releasing sperm onto eggs put into the water by females. Males of this species typically hold their collective grip on a female for several hours, Dittrich says, but “we know from the literature it can last up to two days.”
Dittrich started wondering about female defenses during an “Oh no!” moment when reviewing video she had captured of European common frogs mating in a lab setup. She had wanted to see if the males show any size preference in the females they target. (Sizewise “not choosy at all,” she reports now. “They grab what they can.”) In the mating videos, however, Dittrich noticed something more interesting.
2023-11-01 07:00:00
Article from www.sciencenews.org