Living high in the tops of the trees, nobody had set eyes on the frog for over a century. But all that changed when it was recently rediscovered in an Indian forest, and found to be much more widely distributed than previously thought. Despite being resurrected, the researchers warn that with the way the environment is being treated across the Indian subcontinent, the chance is still there that it might be lost again, but this time forever.

Originally classified as Polypedates jerdonii after the zoologist who first caught it, following DNA testing on the amphibian the researchers who rediscovered it found it to be so genetically distinct from all other species of tree frog that it warrants being given its own genus. The frog is now classed as Frankixalus jerdonii, and brings the number of frogs discovered by the renowned Indian biologist Sathyabhama Das Biju to an impressive 79.   

^{The frog is thought to be found throughout India and even into China, though it is threatened by habitat destruction. Biju et al, 2016.}

The frog was last recorded in the wild in 1870 by Thomas Jerdon, and since then presumed extinct. That is until 2007, when a team of researchers hunting for other amphibians on the forest floor heard an unusual call emanating from the canopy. “We heard a full musical orchestra coming from the tree tops. It was magical. Of course we had to investigate,” Biju, the lead author of the paper published in PLOS ONE in which the new discovery is described, told the Associated Press.

When they got up there, they rediscovered the species of frog not seen for over 130 years, which they found to breed in the holes of the trees. They also discovered that it went about this in a rather strange way. First, the female will lay some fertilized eggs in the little pool of water contained in the hole, and then disappear and wait for them to hatch. When this has happened, she’ll return at regular intervals and deposit unfertilized eggs in order to feed the growing tadpoles.

^{The unusually smooth mouth of the tadpole is thought to be adapted to a life of oophagy, or eating eggs. Biju et al, 2016.}

This unusual strategy helped to explain why the mouths of the tadpoles lacked teeth like most species and were instead smooth, allowing them to suck the eggs in. The adults deviate from the norm, as rather than eating insects and larvae like almost all other amphibians, they choose to dine mostly on vegetation.

While the announcement of the frog’s rediscovery is obviously welcome news, Biju warns that it shouldn’t make people complacent. Amphibians around the world are facing enormous threats, with the International Convention for the Union of Nature estimating that a third of all amphibians are on the brink of extinction. And F. jerdonii is no exception, as even since being found in 2007, the researchers note that the forest has been subject to slash and burn and tilled for agriculture.