Night frog species uses a never-before-seen mating method

An elusive, nocturnal breed of frog native to the Western Ghats region of India has a few never-before-seen tricks up its sleeve when it comes time to get intimate, as scientists have found that the creatures use a previously unknown mating position when actively reproducing.

Sathyabhama Das Biju, an amphibian expert from the University of Delhi, and an international team of colleagues were studying Bombay night frogs (Nyctibatrachus humayuni) in the forests of the Western Ghats for weeks before finding out that the amphibians utilized a sexual position previously unknown to science, adding to the six already known to be used by frogs.

According to Science News, video footage shows the male frog positioning himself loosely on the back of the female, with his limbs on the ground, tree branches or leaves in a position known as a dorsal straddle. He then releases his sperm onto her back, and leaves before the female lays her eggs. She then lays the eggs, and the sperm trickles down her back and legs onto them.

To date, Bombay tree frogs are the only of the more than 6,600 known species of frogs to use this technique, The Guardian noted, and in most cases, the male directly grasps onto the waste, armpits or head of his mate. However, in this case, they steadied themselves using branches or leaves that were nearby before releasing his sperm directly onto the female’s back.

‘A new chapter in the frog Kama Sutra’

When asked why the frog might have started using this unusual mating technique, Biju told The Guardian, “We have no idea.” Nonetheless, he and his colleagues have detailed their findings in the June 14 edition of the journal PeerJ, calling the discovery “striking” and “unique.”

However, the unusual reproductive approach is not the only unusual thing that the research team discovered about the Bombay tree frogs. They also discovered that the females are the 25th type of frog species to produce a call, that there are territorial fights between the male members of the species from time to time, and that they are the first type of Indian frog known to eat snakes.

Of course, their sexual behaviors are the most noteworthy discover, though the breakthrough did not come easy for Biju. He originally spotted two Bombay tree frogs getting intimate in 2002 but since the species is so elusive, for years he was only able to catch a quick glimpse every so often. It wasn’t until eight years later that he launched a concerted effort to observe their mating habits, and even then, it took more than 40 days for his team to obtain the footage they sought.

“It has been a wonderful experience to observe the entire breeding sequence of this unique frog. It’s like watching a scripted event,” Biju told National Geographic via email. “So far, this mating position, is known only in Bombay night frogs,” he added. Noah Gordon, a herpetologist at the University of Evansville who was not involved in the study, stated that the discovery “creates a new chapter in the frog Kama Sutra.”

—–

Image credit: University of Delhi