The Yellow-Bellied Bell Frog may decide to turn a male into a meal if its call is not captivating enough.
John Gould, an ecologist at the University of Newcastle, heard a terrifying sound while conducting post-doctoral research on the declining numbers of the Yellow-Bellied Bell Frog. In the pond he was surveying on Kooragang Island, north of Sydney, he witnessed a large female frog chewing on the hind leg of a male frog while slowly pulling it down into a hole. “The male frog was doing its best to prevent this from happening,” Gould recounted.
Female frog biting male frog for a meal. (Photo: John Gould).
Instances of cannibalism among adult individuals have been recorded for the first time in the Yellow-Bellied Bell Frog, prompting Gould to investigate further. He ultimately concluded that when a female Yellow-Bellied Bell Frog is dissatisfied with a male’s song, she may turn her partner into a meal. According to Gould, the female frog is almost the ultimate predator of the male, as their ears are perfectly structured to detect the calls of potential mates.
Cannibalism is a common behavior among amphibians. However, typically only the smallest frogs, toads, or salamanders become meals. The tadpoles of many species also consume smaller tadpoles to grow. In some cases, males may eat eggs or larvae; for instance, a male hellbender salamander may consume its young when faced with scarce water conditions.
However, researchers rarely observe adult cannibalistic behavior in amphibians. In a study published in the journal Ecology and Evolution, Gould reviewed the literature and found only two examples of adult frogs preying on other adult frogs in a laboratory setting, where the female was larger than the male. In the Yellow-Bellied Bell Frog, females can reach approximately 7 cm in length, while males max out at just under 5 cm. Gould suggests that females can determine whether a male is suitable for mating or for eating based on its call. This means that male frogs face significant risks while trying to attract mates.
David Pfennig, a biology professor at the University of North Carolina at Chapel Hill, wants more evidence of adult female frogs preying on males before confirming this as a common phenomenon. While females may benefit from eating males, they could also pay a price. Males might retaliate or cause the females to choke on oversized bites. Cannibalistic behavior could also spread disease within afflicted populations. According to Gould, after some struggle, the female frog pulled the male deeper into the hole. The male called out again and then successfully wriggled its hind leg free from the female’s mouth and escaped.
