Frogs and toads are surprisingly sexually liberated. With over six common ways to do the dirty, they are actually the most adventurous group of animals around, practicing the “head straddle” to the “glued” stance. But researchers have now described a seventh way that frogs go at it, and the new position is... unconventional, to say the least.
The Bombay night frog – which itself already sounds like a sex position – lives in the Western Ghats of India, a known biodiversity hotspot due to its lush tropical rainforest. When the monsoon rains come, it signals the start of the breeding season for the frogs, and the males start to woo the females by singing her a sonorous love song. If the female likes what she hears, she then lets the male climb on top.
Something akin to an anuran Kama Sutra. The new mating position now brings the number of known positions to seven. SD Biju
So far, so conventional. But this is where things start to get a little different. Rather than grabbing onto the female as is the case in most other amphibians, the male will straddle her, bracing himself against the tree or leaf to which she clings. Then things get… a little messy shall we say. He coats his sperm onto her back before dismounting. The female then releases all of her eggs, and allows the sperm that is dripping off her back to fertilize them. The eggs stay stuck to leaves overhanging water, into which the tadpoles drop when they hatch.
This all adds up to some pretty unusual mating behavior, even for frogs. “Our study has highlighted several unique features about the Bombay Night frogs,” explains the University of Delhi’s Professor SD Biju, who led the latest study describing the dorsal straddle in PeerJ, to IFLScience. “The major highlights include: New amplexus mode, fertilization of eggs without physical contact between the sexes, male ejaculates sperms on female’s back, females [calling], and male-male combat.”
Out of nearly 7,000 species of frogs and toads (known as anurans), in only 25 of them are the females found to call to the males, and only in 5 are the male known to ejaculate on the female's back during sex. The mixtures of these already rare behaviors therefore make the Bombay night frog (Nyctibatrachus humayuni) something of a peculiarity even among the anurans.
But the discoveries didn’t even stop there. After the frogs had done the deed, the researchers watched in amazement as a snake came in to undo all of their hard work. “This study documented snakes preying on eggs of Bombay Night frogs,” Professor Biju told IFLScience. “This is the first such report not only for this species but also for any Indian frog.” Previously, this has only been observed a handful of times, and all in South America.
A snake was observed feasting on the frog's eggs. A first for not just this frog species, but for all amphibians in India. SD Biju
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