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In the Laterite Plateaus of Maharashtra, Rock Bottom is a Wonderful Place

The rocky outcrops of the northern Western Ghats are often considered wastelands, when they are hotbeds of endemic diversity.

Text by Varad B. Giri and photos by Dhritiman Mukherjee

It was the peak of summer and I was pushing my flat-tyre motorbike on a rocky outcrop near Malvan, in the Sindhudurg district of Maharashtra. Around me was a rocky, barren landscape interspersed with dry grass and stunted, bushy plants. There was no sign of activity, and the midday sun was scorching, adding to my agony. I had just finished my Master’s in science at the time, and was starting to learn about birds and reptiles through small field outings. The purpose of the Malvan trip was to photograph wildlife, but the bubbly enthusiasm with which I had set out on my happy mission was deflated after pushing the bike, alone, for one and half kilometres.

At the time, with my limited understanding of natural history, I remember thinking, “What the hell could survive here?” It was my first rendezvous with the rocky outcrops of the northern Western Ghats and it left me barren of enthusiasm. My sentiments were echoed by government land-records, local communities, and many of my friends who considered these outcrops largely barren, and devoid of life.

Over the years since that trip, my passion for the natural world morphed into a profession. I joined the iconic BNHS, and suddenly, birdwatching and snake-catching trips became avenues of scientific exploration. On one such expedition, mainly to study the caecilians, we were exploring different habitats and landscapes of the northern Western Ghats. For three days, we meticulously searched pristine forests and plantations, but not a glimpse of a single caecilian. Somehow, destiny brought me and my bike to the same plateau near Malvan, but this time I was with my friend Swapnil Pawar, and other team members. It was the monsoon season, and as soon as we hit the plateau, a heavy shower started so we took a refuge under a small tree on the border of the plateau and waited.

The plateaus of the Northern Western Ghats were formed around 65 million years ago, during the deccan trap volcanic eruption, which lasted about 3 million years. It is composed of mainly laterite rock, rich in iron and aluminium content.  Cover photo: The Western Ghats are considered a biodiversity hotspot, and the rocky outcrops of the mountain range are no different. Characterised by red, laterite rock, these habitats foster a number of endemic species, such as the critically endangered white-banded viper gecko that is seen on only a few coastal rocky outcrops in the Ratnagiri and Sindhudurg districts in Maharashtra.

The plateaus of the Northern Western Ghats were formed around 65 million years ago, during the deccan trap volcanic eruption, which lasted about 3 million years. It is composed of mainly laterite rock, rich in iron and aluminium content.
Cover photo: The Western Ghats are considered a biodiversity hotspot, and the rocky outcrops of the mountain range are no different. Characterised by red, laterite rock, these habitats foster a number of endemic species, such as the critically endangered white-banded viper gecko that is seen on only a few coastal rocky outcrops in the Ratnagiri and Sindhudurg districts in Maharashtra.

We were standing next to a big, rocky outcrop with no soil — not a suitable habitat for caecilians — but to beat my boredom, I upturned a nearby rock (usual practice to search for amphibians and reptiles). To my surprise, there was a swamp eel, a fish that looks like a caecilian but lacks rings and has a flat tail. Encouraged, I turned another rock and this time, I yelled with joy and started dancing — a caecilian, the first in three days! Rather than rushing to see my discovery, my team members dispersed to start their own search.

To my pleasant surprise, there were caecilians under many rocks, and one of our teammates, Ravindra Bhambure even found a gathering of 21 caecilians under one, small rock — one of the best experiences in my life! Overall, we counted 230 individual caecilians, three saw-scaled vipers, one unidentified wolf snake, two striped keelback snakes, frogs belonging to three genera, and plenty of scorpions, all in one, small corner of this plateau. So much for “barren” landscape!

This episode changed my perception towards the rocky plateaus of northern Western Ghats, locally called sadas. I began visiting them more, reading about them, and discussing their importance with likeminded people. The best information about this ecosystem can be found in the publications by Dr Aparna Watve, who has published amazing articles on the importance of this habitat and started long-term conservation initiatives in the region too.

    
The brown scorpion (Hottentota sp.) is a common inhabitant of these rocky plateaus, as is the swamp eel (Monopterus sp.), a species of air-breathing fish that is often spotted under rocks.

The brown scorpion (Hottentota sp.) is a common inhabitant of these rocky plateaus, as is the swamp eel (Monopterus sp.), a species of air-breathing fish that is often spotted under rocks.

If you visit the mountains of the northern Western Ghats, especially between 160 to 180 N, you’ll notice that they have flat tops ranging from 700 to 1200 meters above mean sea level. These ‘plateaus’ or rocky outcrops are also seen along the Konkan coast and have very little soil. Constant exposure to high temperatures in the summer and heavy rains during the monsoon makes them inhospitable for floral diversity in general, but have resulted in a breed of ephemeral and endemic plants, that are found exclusively in this region.

Thus, a plateau that is barren in summer metamorphoses into a piece of heaven in the monsoon, blanketed with plants that bloom for a short span at the end of the rainy season, from September onwards. Close observation shows that the vegetation growing on these rocks, around them, and in their crevices, are all entirely different. Every aspect of these rocky outcrops is a micro-climate, utilised by the vegetation in wonderous ways. The Kaas plateau, near Satara, is an example of this unique diversity, and is on the Unesco World Heritage Site for its endemic biodiversity.

The faunal diversity is equally mesmerising and changes seasonally but, unlike for plants, dedicated inventories of the animal species in these rocky outcrops are wanting. The major faunal elements I observed are different kinds of insects, arachnids, amphibians, and reptiles. There are a few grassland birds like pipits and larks that frequent these habitats, and a few species of raptors use them as vantage points. The mammals I have observed include the Indian gaur, sambar, leopard, sloth bear, wild boar, porcupine, wild dogs, even tigers that frequent these rocky outcrops for feeding, drinking water, or resting.

This habitat has a thriving population of snakes, ranging from the venomous Ssaw-scaled viper (Echis carinatus) (top), to the relatively harmless Sstriped keelback (Amphiesma stolatuma) (below)

This habitat has a thriving population of snakes, ranging from the venomous Ssaw-scaled viper (Echis carinatus) (top), to the relatively harmless Sstriped keelback (Amphiesma stolatuma) (below)

I was keen to know about herpetofauna — the amazing world of amphibians and reptiles — and wondered if these hostile conditions support any of my beloved herps. Guided by curiosity, I began observing the diversity of amphibians and reptiles more closely, and after many years, and many trips, I now feel like I have a brief understanding of the variety of herpetofauna that frequents these places.

During the dry season, the reptiles commonly seen here are saw-scaled vipers (Echis carinatus) and lizards of the family Lacertidae (Ophisops beddomei and Ophisops sp.). These species are mostly seen in arid landscapes, and has biogeographic affinities with European and middle-eastern species. The other common reptile seen in this habitat, is an undescribed species of lizard, Hemidactylus sp.. Among the amphibians, the cricket frogs (Minervarya spp.), Indian bull frog (Hoplobatrachus tigerinus), and skittering frog (Euphlyctis sp.) are regulars. Interestingly, all these species breed on the rocky outcrops during rainy season, so what happens to them during the monsoon? Are these the only herps in these habitats, or are there any endemic species? These are the questions I asked myself every time I visited these habitats, the more marvels I unearthed.

With the arrival of monsoon, these rocky outcrops are transformed into a buzzing ground for many amphibians and reptiles, few of them confined to this habitat. A genus of toad Xanthophryne, which is represented by only two species is one such representative example. The Koyna toad (Xanthophryne koynayensis) is known to inhabit only rocky outcrops in the Sahyadri Tiger Reserve in Sangli and Satara districts, while the Amboli toad (X. tigerinus) has been found only oin rocky outcrops near Amboli and Chowkul in Sindhudurg district. Both species are strict plateau endemics and breed in the small water that accumulates on exposed lateritic rocks. These toads are rarely seen in the nearby forest.

The rains transform the habitat from brown to green. Small waterbodies are formed across the rocky plateaus, creating a breeding grounds for insects, amphibians, reptiles and short-lived species of flora.

The rains transform the habitat from brown to green. Small waterbodies are formed across the rocky plateaus, creating a breeding grounds for insects, amphibians, reptiles and short-lived species of flora.

Chalkewadi plateau in Satara district is an equally unique plateau, which is also a tourist destination due to its windmill farms. In 2008, a new species of nocturnal lizard, Hemidactylus sataraensis was described from this habitat. This medium-sized, ground-dwelling and cute lizard considered endemic to this plateau, and is mostly seen during the monsoon season. However, one has to carefully turn rocks to see them, to avoid being stung by scorpions or bitten by saw scaled vipers that also take refuge in similar micro habitats. A similar looking gecko, Hemidactylus albofasciatus is found in a few rocky outcrops in the coastal region of Sindhudurg and Ratnagiri districts. Genetically, these two are sister species and are considered as threatened by IUCN owing to their restricted range and continued decline in the quality of habitat.

In 2016, another new species of a lizard, Sarada superba was described from the same plateau. This spectacular species is presently known to inhabit only this landscape. These lizards are active during the summer and the entire plateau is teeming with territorial fights and breeding displays. Males have a colourful fan on their throat, which they display to attract the females. One of the pioneering studies on the ecology of this lizard is done by Aamod Zambre and Harshal Bhosale of Maria Thacker’s lab from Indian Institute of Science, Bangalore. They also observed changes in behaviour and other traits in the fan-throated lizards found on the plateaus with and without windmills. This was mainly due to the lack of predatory pressure as birds of prey avoid places with windmills.

The Amboli toad (Xanthophryne tigerina) is another endemic species, confined to rocky plateaus near Amboli, in the Sindhudurg district, Maharashtra. Can you spot the toad in this picture? (It’s sitting in a depression in the rock, just right of centre)

The Amboli toad (Xanthophryne tigerina) is another endemic species, confined to rocky plateaus near Amboli, in the Sindhudurg district, Maharashtra. Can you spot the toad in this picture? (It’s sitting in a depression in the rock, just right of centre)

During one of our explorations of the plateaus on Amboli and Koyna, we came across a small, green snake with black dots and a pigmented belly. They were the juveniles of a rare snake, Rhabdops aquaticus, a genus and species endemic to the Western Ghats. Interestingly, the dorsum (back) of these juveniles is green — strikingly different from their adults, which are dark brown. One reason for this colour change could be camouflage: Our monsoon observations of the juveniles were always on rocky plateaus, where the snakes take refuge under rocks in waterlogged areas with fresh grass. Similarly, the adults are aquatic and forage at the bottom of forest streams in the night. Thus, the brown dorsum aids them in camouflage.

A juvenile Rhabdops aquaticus, a rare, aquatic snake often seen on rocky plateaus in Maharashtra.

A juvenile Rhabdops aquaticus, a rare, aquatic snake often seen on rocky plateaus in Maharashtra.

In addition to supporting many unique and endemic lineages of plants and animals, these rocky outcrops are beneficial to humans too. Topographically, these plateaus are atop mountains and many small streams originate here. During the monsoon, when these rocky outcrops receive heavy rainfall, the streams swell, and distribute water to nearby landscapes. The laterite rock also acts like a sponge by retaining water in their porous structure, and slowly distributing it to streams nearby. Any damage to these plateaus will disturb the water table in the region.

Despite providing these crucial ecosystem services, this habitat still has a ‘wasteland’ tag on government records, and is under tremendous anthropogenic pressure. Mining is a major threat, but in recent years, people are also converting some of the plateaus into mango orchards. It is crucial to understand that not only the species, but entire habitat is critically endangered and deserves utmost protection. Far from wastelands, these are some of the ‘best’ lands for diverse flora and fauna.

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