Environment

Frogs, Birds, Lizards: What’s Behind the Spate of New Discoveries in India?

From frogs to lizards, we have plenty of new species about which to be excited  – and worried – this year.

A Himalayan forest thrush in song. Credit: Craig Brelsford

A Himalayan forest thrush in song. Credit: Craig Brelsford

Deepak Veerappan was in-between research jobs when, out of boredom, he started exploring the parched open lands in the south and west of India. He ventured out on his own into sun-baked landscapes in search of a “fan-throated lizard” – a small lizard with a large double chin. His post-doctoral position at the Indian Institute of Science, and thus funding, were yet to come but he had already laid the foundation of what would keep him busy for the next few years.

Only two species of the unusual lizards Veerappan loved watching had been known from India. From observing them in the wild, he knew there were actually more than two. This led Veerappan to discover five new species of fan-throated lizards – named so because the males have loose, stretchable skin hanging from their necks.

This spectacular find is one among a slew of discoveries we have seen so far this year in India. Wherever you look, be it the shores in the south or mighty mountains in the north, sun-scorched lands of the west or wet hills of the east, new species are being found everywhere. And yet scientists say there’s more to come. What on earth is going on?

One of the five newfound fan-throated lizards (Sarada superba) Credit: Varad Giri

One of the five newfound fan-throated lizards (Sarada superba). Credit: Varad Giri

Advanced and affordable laboratory techniques have, for one, opened up discoveries such as that of the fan-throated lizard.

“Molecular methods are very important; an easy way to find out how variable the population you are studying is,” says Veerappan, who used these together with physical characteristics of lizards (such as their colourful, stretchable necks) to identify new species.

These methods have also made discoveries more reliable, according to amphibian researcher K. V. Gururaja of the Gubbi Labs. Measuring physical characteristics, Gururaja says, is subjective and can introduce error, but with molecular methods, “whether it is the case of DNA fragments I collect and analyse or someone else, finally what you are going to get is quite similar sequences.” Comparing the chemical readouts of a few genes from a likely candidate with those from known species can tell us if the species in question is indeed new to science.

Gururaja recently reported two new species of frogs based on how they look and sound, and fare genetically with known species. The new frogs have calls that are distinct in length, pitch and structure. 

One of these, the Honnametti bush frog (Raorchestes honnametti), was found in the Western Ghats. It is a small-sized frog that goes “treenk treenk treenk when active at night. The frog remained unnoticed due to its superficial resemblance to other bush frogs.


Calls of the bush frog. Credit: K.V. Gururaja

At first look, even Gururaja didn’t think the frog was new, but then it occurred to him that its range is further south and east to that of the frog it resembles. “In between there is no forest where the frog would have come from,” Gururaja soon realised. He then proceeded to carry out detailed studies of the frog’s morphology, advertisement calls and genes – all of which gave its unfamiliarity away.

The Honnametti bush frog. Credit:  K. V. Gururaja

The Honnametti bush frog. Credit:  K. V. Gururaja

The Honnametti bush frog is commonly found in the Western Ghats and is not threatened by human activity because its range lies in a protected tiger reserve. However, the frog that followed its discovery is rare and rather unprotected. 

Microhyla laterite or the laterite narrow-mouthed frog is found outside protected areas, in wasteland. This so-called “wasteland frog” has a range of about 146 squared kilometres, thus meeting the “endangered” category criteria on the International Union for Conservation of Nature’s Red List of threatened species. Its presence in land used for dumping waste means the frog enjoys no protection at all.

To Gururaja, its discovery reiterates that species may be present in neglected or overlooked places. What one thinks of and categorises as wasteland “could be a breeding ground for a new species,” he says.

The laterite narrow-mouthed frog. Credit: Saurabh Sawant

The laterite narrow-mouthed frog. Credit: Saurabh Sawant

M. laterite went undiscovered so far partly because it sounds more like an insect than a frog, with its cricket-like “zeeee zeeee zeeee” calls. “That’s the most amazing fact,” quips Gururaja. Its identification was made possible by an integrative approach, one that deploys new acoustic and molecular tools alongside classical taxonomy.


Cricket-like calls of the wasteland frog. Credit: K.S. Seshadri

Improved methods in taxonomy may have made it easier to uncover new species, but they are not the only reason we are finding more and more species of frogs, lizards and snakes. Another reason is that the field of herpetology (the study of amphibians and reptiles) has remained largely under-explored since India gained independence. 

A post-doctoral research fellow at the National Centre for Biological Sciences in Bangalore, Varad Giri explains that our current knowledge of species diversity is based on collections made during British rule. But even during that time naturalists mostly sampled species where they were based, adds Giri.

“No one had made an effort to visit all the places, collect a targeted species and then work on it,” Giri says.

But discoveries began to pick up at the turn of the century.

Veerappan’s discovery of fan-throated lizards, to which Giri contributed in the capacity of a taxonomist, is an example of such a fine-scale study that was long overdue. Researchers knew more species of lizards were out there but someone had to look into their habitats, which are scattered over several thousand square kilometres across the country. Veerappan and Giri are confident that more discoveries await them.

Sitana spinaecephalus, one of the five new species of fan-throated lizards. Credit: Deepak Veerappan

Sitana spinaecephalus, one of the five new species of fan-throated lizards. Credit: Deepak Veerappan

Giri was also part of another team that recently found a new snake species in a museum specimen and confirmed its existence in the Western Ghats. The revelation came 145 years after it was wrongly identified for its cousin. Since 1871, the snake has lurked unknown in dark and dusty museum cabinets, much like its living relatives deep in the forests.

Melanophidium khairei is a burrowing snake that lives hidden in soil and is mostly seen venturing out at night. It was identified based on a host of morphological characteristics – size, colour pattern, number of lustrous scales on its body and number of teeth, among other features.

Museum finds such as this are becoming increasingly common. But access to historical collections is still an impediment facing Indian researchers. Most “type specimens” – based on which species or their groups are described – are stashed away in museums across Europe.

Melanophidium khairei, found in a museum and eventually confirmed in the wild. Credit: Varad Giri

Melanophidium khairei, found in a museum and eventually confirmed in the wild. Credit: Varad Giri

Seated in a quiet reading room away from school kids dashing about the galleries of the Natural History Museum (NHM) in London, S.D. Biju speaks of the main challenge behind taking such museum trips. Biju, who is a frog researcher with 80-odd species to his name and a professor at the University of Delhi, says that sometimes one has to visit a museum abroad to study just one specimen. Though it is important to do this, it is obviously expensive. It is different with the NHM though, as “almost 50% of our historical specimens are curated in this museum.”

Even within India, one might still have to travel across the country. “There is a new trend of every institution keeping their specimens. Scientifically, that’s not a good idea,” Biju says, voicing the need for “a centralised type collection centre.” 

When Veerappan was travelling to study fan-throated lizards found in the dry zones, he was also visiting museums to study the specimens kept in each. It was through field and museum observations that he figured out that there were undiscovered species out there. “That’s why museums are very important as repositories and that’s why we need them to be maintained,” he says.

Having specimens in a central repository avoids duplication as well. “Some years down the line, if there are more researchers who want to study the same group, they don’t have to go out and do the same sampling again,” Veerappan says. Visiting a museum will tell them which specimens are from where and for which data is already available. In which case, Veerappan says, one would rather concentrate on areas that are under-sampled. 

But what about situations when having everything in one place is a disadvantage?

Take the 1943 flood of the river Varuna, which flows through Banaras (Varanasi). The Zoological Survey of India’s (ZSI) entire collection was then temporarily housed out of a building complex, called Kaiser Castle, situated on the banks of the Varuna when the river began to swell. Soon the floodwater inundated rooms full of specimens, overturning racks and shattering glass jars. When the water receded, it carried with it the labels of the specimens that were still intact. 

It is ironic that the ZSI had been moved to Banaras from its original location in Calcutta (Kolkata) for fear that Japanese air raids during the Second World War would destroy its vast collections. 

One would think we are better prepared in 2016 than in war-time India. But a fire that broke out last month at a science college of Calcutta University destroyed over 4,000 specimens.

The incident should have alarmed other institutions. Yet this week, the National Museum of Natural History in New Delhi went up in flames.

One has to wonder how many more accidents it will take before our museums take requisite preventive measures.

New species hidden away

Dividing their time between museums, field and laboratory, researchers are adding new knowledge of new species every day. A lot of their finds are serendipitous: researchers say they don’t go looking for a new species, but usually find them while studying something else.

This is exactly what happened when Biju was surveying amphibians of north-east India in one of his monsoon expeditions. Biju and his colleagues were walking through a forest at sundown when they heard calls coming from the canopy. The calls were not of a bird but of a frog that lives in trees.

Frankixalus jerdonii, or the tree hole breeding frog, as it is popularly known, has an unusual way of life – it lives and breeds in rainwater-filled tree holes. The female lays eggs that stick to the inside walls of the tree hole. And as if that isn’t unusual enough, the tadpoles feed on unfertilised eggs that their mother offers them as food.

“The frog has been rediscovered and was originally described almost 150 years ago and then nobody had ever seen it in the wild,” says Sonali Garg, a PhD student in Biju’s lab.

Using external morphology, skeletal features, breeding behaviour, tadpole morphology and molecular data, Garg and her team found that the frog was different from other tree frogs.

But an obvious threat looms over the survival of these forests and the unique frogs they nurture. “The forests where we have found these frogs are facing slash-and-burn cultivation,” says Garg. Without trees, the frogs will not be able to reproduce. 

The tree hole breeding frog. Credit: S.D. Biju

The tree hole breeding frog. Credit: S.D. Biju

With 400-plus species reported from India so far, research on frogs and toads has been riding the crest of the discovery wave, especially in the past few decades. But new finds seem to have stagnated for other animal groups such as birds. Bird discoveries are so rare in India that since 1947 only four new species have been found.

Uppsala University’s Per Alström, who led the latest of the four Indian bird finds, says discoveries are few because “India has been extremely well-studied with respect to its birdlife, thanks to the influence by Dr. Salim Ali”.  

Zoothera salimalii, the Himalayan forest thrush, remained undiscovered since, being a ‘cryptic species’, it closely resembles its cousin, the plain-backed thrush, in appearance but is genetically different.

When Alström heard thrushes singing during a field trip in 2009, he realised that they sounded “strikingly different” at different altitudes and habitats. The ones found above the tree line, in the alpine zone, had a harsh, rusty song, whereas the ones found in the forests were more soft and musical.


The harsh song of the Alpine thrush. Credit: Per Alström

Soon it dawned upon him that the songs were not of the same species. But it was only after a detailed comparison of their plumage, song, distribution and DNA that the birds were identified as two separate species. For this, Alström and his team had to study specimens curated in 15 museums scattered across seven countries.

Alström renamed the “original” plain-backed thrush breeding above the tree line the Alpine thrush and christened its newfound musical cousin found in the Himalayan forests after ornithologist Salim Ali. He suspects there are more such cryptic species to be discovered in India.


The soft, musical song of the newfound Himalayan forest thrush. Credit: Per Alström

Just as the extensive work of “Birdman” Ali has put our feathered friends on the map, “Frogman” Biju’s has done the same for, well, frogs. Gururaja credits Biju for spurring the next generation’s froggy interests: “His discovery of the pig-nose frog pushed many youngsters into frog research.”

Gone are the days, Gururaja points out, when people would collect animals and hand them over to an authority – a taxonomist – for identification. “Nowadays, people go out in the night hours, they do their own research, go beyond the regular routes, they venture into forests.”

This has been made possible by access to camping gear, which allows researchers to spend hours studying animals active only at night. “[Researchers] have the accessories to do field work compared to earlier days when you had to really struggle to get any of these things,” Gururaja says. “That’s why more species are being discovered. There are many more to be described.”

But could frogs go the way of the birds, in terms of our discoveries of them? In the next 20 to 25 years, Gururaja reckons, the number of new species being described will saturate. Finding species though, he is quick to warn, “is not an end in itself”; that a lot of the species are data-deficient is also a problem. Their abundance, ecology and evolution matter in their conservation, not just their discovery.

Richa Malhotra is a freelance journalist. She reports on science, wildlife and the environment.