A pair of Bombay night frogs perform the dorsal straddle. Photo by SD Biju
MUMBAI, June 14 (UPI) -- Frogs are some of the kinkiest amphibians in the forest. Biologists have identified six different sex positions among the planet's 7,000-plus species of frogs and toads.
Recently, scientists discovered a seventh position -- dubbed the "dorsal straddle" -- being employed by the Bombay night frog, Nyctibatrachus humayuni, a species endemic to India's Western Ghats.
If the dorsal straddle doesn't sound very intimate, that's because it's not. The position involves no genital contact. The male frog straddles the female from behind using a branch or leaf to brace himself while he deposits his sperm on the female's back. The female lays her eggs, which are fertilized by the sperm trickling down her backside.
A team of researchers led by Sathyabhama Das Biju, from the University of Delhi, spent a few dozen nights filming the sex lives of Bombay night frogs.
Though the technique is derivative of a common frog sex position called amplexus -- comparable to "doggy style" -- researchers say the dorsal straddle is unique.
"This is a remarkable frog with an unprecedented reproductive behavior, which is unique for a number of reasons," Biju said in a news release. "This discovery is fundamental for understanding the evolutionary ecology and behavior in anuran amphibians."
Biju and his colleagues published their findings in the journal PeerJ.
During their time in the forests of the Western Ghats, a mountain range running the length of India's west coast, the scientists observed females calling to males, in addition to males calling to females -- a behavior observed in just 25 frog species. Researchers also witnessed a snake eating a clutch of the night frog's eggs, a first.