Frogs in fragments

 

I think Kalakkad Gliding Frogs (Rhacophorus calcadensis) have amazingly beautiful eyes.

When Divya asked whether I would be interested in doing some herpetofaunal surveys in some rain forest remnants in Valparai, I didn't have to think twice to say 'YES!' Though I had been visiting the area since 2006, I did not have many opportunities to get to know the herpetofauna of this region very well. So it was that in October 2017, I went to Valparai to start the surveys. The targets were a few small rain forest remnants on the western edge of the Valparai plateau, at the border between Tamil Nadu and Kerala. Sridhar took me to the field station at Shekhalmudi while Sunder Raj, the field assistant reached a little later on a motorcycle that was to be our field vehicle. A little later, Anand and family also came and we all had dinner at the base camp that evening.

Sholayar, with Kerala on the left and Tamil Nadu on the right. Candura remnant is towards the upper right quadrant of the image.

 Murugali-Candura rain forest remnant is an abandoned vanilla plantation that was grown under the shade of rain forest trees. Spread over 100 ha, it is bordered by tea plantations, reserved forests, and the Sholayar river. With the support of Parry-Agro Industries Ltd, NCF's rain forest restoration team has been working here over the last several years to bring back native rain forest species.

I stayed there for the next couple of months, surveying the herpetofauna of these small rain forest patches. Our routine was somewhat like this. I would go with Sunder Raj to one of the sites in the morning, conduct a few simple visual surveys:1 hour survey, 15 minutes tea with biscuits, and repeat. We would usually get back to base camp by 2 in the afternoon, by which time it often started raining thanks to the northeast monsoon. Usually, I spent the afternoons trying to figure out identities of species by going through taxonomic publications. This turned out to be tedious and sometimes infuriating work as one noticed inconsistencies, errors, or plain vagueness of many species descriptions. Not that these were invalid species, but the features used to describe some of them were of little help in identifying many individuals in the field. Once I had enough of that frustration, I usually made a cup of black tea and watched the rain for a few minutes. 

Views from the field station, rainy days vs non-rainy days.

About half an hour before sunset, we would be riding again through tea plantation roads, usually back to the same site as morning, to have a quick walk around the area before night surveys. This was done primarily to avoid bumping into elephants at night. This was an additional precaution since I was already getting information about elephant movements in the area through the Elephant Information Network, an initiative of NCF to manage human-elephant interactions in the region. If we had information that elephants are likely to be in a particular area, or if we found evidence of their presence during our evening surveys, we usually rode in the opposite direction to the farthest site possible. Even then, once or twice, we heard deep rumbling noises coming from the surrounding forest while I was walking along streams trying to spot tiny frogs. But other than that, we never had any trouble with elephants. But we did run into gaur a few times, and these encounters can be particularly interesting when you are riding a 110cc bike along rocky paths, with a pillion, on a rainy/foggy night. There was one particular bull that used to come out of the forest where the path entered it. This place has a bridge over a stream, lots of grass on one side, and a sharp bend in the road, such that he would often be hidden from view until you make the turn. When we did see him there, we had to make a quick u-turn, ride back another 50 m or so, and allow him time to move away. And when we returned later in the night, we had to repeat this process from the other end of the road. Occasionally, we would hear a barking dear, the sawing calls of a leopard, and one time, news from plantation workers about a tiger that had killed a gaur somewhere in the vicinity. I only hoped to never meet it at night.

Gaur (Bos gaurus), probably the most commonly encountered large mammal on the Valparai plateau.

Unsurprisingly, these surveys revealed many species of amphibians and reptiles, even in the smallest rain forest remnants. Over the two months, I found 36 species, including 19 species of frogs, one caecilian, and eight species of lizards and snakes each. Yet, I was sure that this was an underestimate of the true number of species present there. I wanted to continue the surveys in the next monsoon, but could not due to work. But luck came in the form of Vijay Karthick, who wanted to do his masters dissertation work on herps in the forest remnants in Valparai. Vijay included many of the forest remnants I had surveyed in his study, including Candura. Though I could not do surveys that year, I managed to visit him and some new sites that I had not previously gone to and see more species.

A sample of the herpetofaunal diversity of these small patches of forests.

I wanted to continue the surveys in Candura as a sort of monitoring programme for herpetofauna. So, I went there again in 2019, this time timing my visit with the beginning of the monsoon when most frogs in the region seem to breed. I was sure that this time, I will add a lot more species to the list. Alas, for the length of time I was there, there was absolutely no rain! Monsoon was greatly delayed that year, and I wonder what happened to all the frogs that planned their activities to coincide with the rains. Still, I managed to complete the surveys and even add a couple of species to the list. I was determined to continue the work during the monsoons of 2020, and then Corona virus entered the picture and you  know what happened after that.

It's not just snakes and frogs. This matrix of plantations and forests support a huge variety of life.

Once again, the prospects for this year look bleak.  But I hope I can continue this work - I really want to know what happens to these animals as restoration efforts continue and the forests recover. Also, there is a joy in revisiting places and getting to know them intimately.