A new frog species where the male frog plasters eggs with mud to protect them from drying out and camouflage them from predators has been described from the Western Ghats of southern India. This is the first time such behaviour has been recorded from frogs, worldwide. A great run for frog lovers as we await the monsoon — this adds to the incredible biodiversity that our mountains harbour.
A team of scientists from Indian Institute of Science and Ashoka Trust for Research in Ecology and the Environment (see below for names and affiliations) have discovered a new species of frog that they have called Nyctibatrachus kumbara, or the Kumbara night frog. The frog is a “night frog”, belonging to the genus Nyctibatrachus — these are some of the most ancient frogs found in India. There are about 27 species already described, all of them endemic to the Western Ghats (found nowhere else in the world).
“The male frog shows such finesse when it applies mud to the eggs, we decided to call it 'kumbara', which means potter in Kannada,” said first author K V Gururaja.
The discovery happened over repeated expeditions to the Kathalekan area near the Jog falls in the Uttar Kanada region of Karnataka, where swamps with a special kind of vegetation — the Myristica swamps — are found. One of the Myristica species gives us the nutmeg spice. In this area, perennial streams are criss crossed by overhanging roots and small rocks, forming small habitats where frogs thrive.
A paper that appeared today in the international journal Zootaxa (May 16th issue) has also described a special behaviour of these frogs. During courtship, males call out to females making a distinctive “tok” sound or a “tok-tok” sound. When the female appears, the male and female stand on their hind legs and use their hands to feel the surrounding surfaces, like overhanging twigs. After mating, the female does an about turn and stands on her hands while laying her eggs.
The male then stands on his hands, gathers mud from the stream and dabs it on the eggs, packing them in place. This is the first time such a behaviour has been recorded in frogs worldwide.
“Mud covering behavior highlights the need of such intricate habitat conditions where species can survive and establish populations,” said DR Gururaja. Any changes to these habitats eventually result in local extinction of species. Such behavioural studies are also important to understand how behaviour in other animals evolved over time.”
Dr. Dinesh, a research scientist at Center for Ecological Sciences, IISc, Bangalore, has earlier discovered 12 new species of this genus from the Western Ghats. He said, “It is always fascinating to work on Nyctibatrachus as I started my career with taxonomic work of Nyctibatrachus. I have been in to most of the hill ranges of Western Ghats in search of them. Now, we have added one more species to the existing list. I am thrilled on seeing the breeding behaviour of mud packing for the first time from the ancient forests — the Myristica swamps”.
Using morphological data (how the frog looks), data from the DNA and from the call patterns of the frog, the researchers were able to identify it as a new species. Ms. Priti, a PhD student and DR Ravikanth, scientist from Ashoka Trust for Research in Ecology and the Environment, have carried out work using DNA to identify Kumbara night frog as a new species.
Ms. Priti says “It has been an exciting phase right from tracking the calls of N. kumbara in the Myristica swamps, watching its unique behaviour and finally working on its DNA. However, with the success comes many challenges as working in the swamps was not easy with the torrential rains and leech bites. This discovery will be helpful in further understanding the evolution of such species existing in the Western Ghats”.
Dr. Ravikanth says “What was more surprising was the fact that a number of researchers had worked in these Myristica swamps and done several surveys (including us a number of times!) but all of us had missed this particular species. After we carried out the DNA analysis, we were really quite excited when we discovered, that Nyctibatrachus kumbara was genetically quite distinct from the other related Nyctibatrachus species. Though this species isn’t imminently at risk, there is a reason to be concerned as a lot of these swamps are under severe threat and hopefully this discovery would draw attention for conserving these unique habitats in the Western Ghats. This discovery once again highlights the fact that the Western Ghats is not yet completely explored and a lot of its basic secrets are yet to be revealed”.