Shaking a Leg with the Kottigehar Dancing Frog

“Kee-kirik-kirik”, played a feeble tune from down the stream. The over-enthusiastic birdwatcher in me was quick to jump to conclusions, and I mumbled, “A leaf warbler I’ve never heard before!” Normally, I would have announced this emphatically to my companions on a nature trail, but I restrained myself this time, for I was in the company of a scientist who knew this forest stream thoroughly. “Kee-kirik-kirik”, the suspected leaf warbler went on. Unable to curb my curiosity, I had barely opened my mouth, than I was interrupted with a “SHHH!” My companion Madhushri Mudke pulled a butterfly net out of her backpack with her gloved hand, made one clean sweep on the stream’s surface, and retrieved the “kee-kiriking-warbler” in the other gloved hand. As you may have guessed, it wasn’t a bird at all. It was an endangered frog, endemic to the perennial forest streams of the Western Ghats, and the animal Madhushri studies — the Kottigehar dancing frog.

Getting my cue that I’d benefit a lot more being a silent observer and taking notes, I watched the Lilliputian in Gulliver’s hands, as we stood knee-deep in a stream at Kalinga Research Centre, Agumbe. Measurements were made, and swabs and photographs taken. I also learned that this species has extremely specific needs — it requires a habitat of 80 per cent canopy cover and perennial streams to thrive in, both of which are being steadily destroyed. It is also particularly vulnerable to changes in habitat and atmosphere. No wonder it is “Critically Endangered” on IUCN’s Red List.

I also learned that its feeble warbling, nothing like the croak of the bull frog or the trill of the skittering frog, is the reason why this frog is a dancer. For an animal that is as invisible as a speck in leaf litter, that needs to catch the eye of a potential mate in a gushing forest stream, warbling simply doesn’t make the cut. The frog’s dance, which scientists call “foot-flagging”, involves alternately stretching the hind legs out rhythmically and flashing the toe webs. It serves a dual purpose: enticing a lady, and warning rival males to stay away. In fact, “foot-flagging” is even deployed as a karate kick to knock a rival off his perch! Many of these features are still hypotheses awaiting validation by experts of batrachology, a sub-branch of herpetology concerned with the study of amphibians including frogs, toads, salamanders, newts, and caecilians. But since I was on this trip because I had to create a cartoon infographic to popularise this frog, I needed fodder to romanticise the creature. I wondered if this merger of science and cartooning would be like oscillating between conservation theory and one’s deep love for the wild!

I’m not sure about the frog’s success rate in attracting a mate, but winning an artist’s heart was a piece of cake. This creature was a treat to draw: a short, pointed dog-like muzzle; an impressive golden ring around the eyes; a bright-white vocal sac, which at rest revealed a lovely pattern of white-and-brown spots; a midline over pale skin; and of course, the famous hind legs — noticeably long, ending in slender toes spaced by white webs. Other members of the dancing frog family, Micrixalidae, may look similar, but can be told apart by sizes, habitat preferences, dorsal patterns, and calls. For instance, we also saw the Niluvase dancing frog (Micrixalus niluvasai), which was smaller, darker, and sang “kee-kee-kee-kee-krr-rr” in this stream. To each dancer his own tune!

Once the dancing male has won the attention and approval of a female, the pair performs amplexus, a more sophisticated term that involves the Indian film censor board’s most hated act. The nuptial pads on the male’s thumbs grasp the female by her axilla (armpit). While sex may be the only thing on the male’s mind, the female must search for a suitable spot to lay her eggs, while still carrying the mating male on her back. A submerged spot with enough loose gravel to dig a cavity up to 8-cm-deep must be selected if the eggs are to survive. The cavity is dug, eggs and sperm deposited, and the female covers it with her hind limbs. Over a hundred tadpoles emerge from this cluster after a fortnight. The handful that survive drying streams, anthropogenic disturbances like pollution, predation from crabs, insects, and birds, diseases, and climate change, will grow up to repeat the “dance” of life another season.

Being poikilothermic (variable internal body temperature) and breathing through their skins, frogs are susceptible to myriad diseases, and human-induced disturbances. Naturalists and wildlife photographers that handle frogs with bare hands are completely oblivious to this fact. The gloves on Madhushri’s hands are just one aspect of the frog-handling protocol outlined by the Zoological Society of London, designed to prevent transfer of pathogens and diseases like Chytridiomycosis, the Covid-19 of the frog world. Use of sterilised equipment, boots, and keeping handling to a bare minimum are additional measures. The temperature of the stream that these frogs inhabit was between 22-24 degrees C, some 15 degrees lower than the human body. A good practice when handling frogs, Madhushri adds, is to sprinkle water from the stream over them, and minimise handling time to under three minutes. This helps reduce stress and bring down their body temperature.

By now, I had begun not just to appreciate the frog’s warbling, but also to differentiate it from Niluvases by their calls. Determined to show off my newfound skills, I kept my eyes and ears out for more signs of dancing frogs. But the further we walked, the feebler the warbles got, until we lost track of our dancers altogether. The stream was appreciably deeper and flowing much faster which could explain the absence of the dancers. Within eyeshot of the spot where we’d measured our frog, seemingly minor changes in habitat had caused a world’s difference in ecology. My ears shifted focus from searching for frog calls to Madhushri’s comments: sudden changes in stream depth, flow, and gradient are just a few natural changes that could make a habitat unsuitable. And many examples of human-induced habitat unsuitability abound in her study sites. While some of her previously marked dancing frog breeding spots are now submerged under faster flowing streams, others have completely dried up or been converted to plantations like areca. Streams outside “Protected Areas” are doubly vulnerable, she warned. “Ah! large-billed leaf warbler”, the batrachologist abruptly announced, pointing at a streamside Calophyllum tree. And my birder-ears pricked in disbelief, having missed an actual warbler’s call completely.

IDENTIFY THE KOTTIGEHAR DANCING FROG

● Size: Smaller than an average person’s fist; measures 2.2-3.5 cm
● Structure: ‘True’ frog
● Dorsum/back: Unspotted, brown in colour, sometimes females show dual colouration of orange flanks and black centre
● Ventrum/underside: Pale whitish, shows variation of brown, spots on the throat
● Habitat: Primary and secondary freshwater streams of the Western Ghats of Karnataka, in low elevation moist, evergreen forests including Myristica swamps

BASIC BIOLOGY

Taxonomy: Kottigehar dancing frog (Micrixalus kottigeharensis) was discovered in 1937. It is one of 24 species of dancing frogs in India.
Evolutionary History: Dancing frogs belong to the family Micrixalidae that diversified more than 60 million years ago.
Habitat and Behaviour: The species shows unique behaviour in the form of “foot flagging” (dancing) and specialisation towards lotic habitats.
Species Conservation: A high Evolutionary Distinct and Globally Endangered (EDGE) score helps prioritise a species’ conservation needs. Though the Kottigehar dancing frog is one of the “100 priority EDGE amphibians” in the world, it currently receives no conservation attention.