Bats of Thar – Vital Cogs in the Ecosystem
Written by Gajendra Singh S
“For as the eyes of bats are to the blaze of day, so is the reason in our soul to the things which are by nature most evident of all”- Aristotle
Thar Desert is one of the most arid environments on earth. This region of rolling sand hills and home of the Great Indian Bustard’s, experiences seasons of sweltering heat, with the temperature rising up to 50oC in the summer months and biting cold with winter temperatures plummeting as low as 4oC in the winter. The rainfall then brings joy to all in this land. The moistened crust welcomes new life, blistering into green patches of scrub forest for a transient period of ethereality. The Thar wildlife finds new life and the resident human beings cultivate their land for a long years survival.
The body of the Thar Desert may seem dry but colorful culture, heritage, havelis, arts and crafts are the soul of this deceivingly pale land. Even today, in this modern time, Thar is home to many endangered species of the world which makes it a region of utmost interest to conservationists and tourists. One such marvelous creature that thrives in this land, is the bat.
Bats are commonly found all over the world, except in the North and South Pole due to the extreme environmental conditions. So far 1,117 species of bats have been reported from all over the world, rendering them the world’s largest mammalian order, Chiroptera, after Rodentia. Of these 1,117 species, 120 species are found in India. So far, 17 species of bats have been reported by various researchers in Thar Desert of Rajasthan.
The order Chiroptera is divided into two suborders namely, Megachiroptera and Microchiroptera. Megachiroptera (old world fruit bats) are large in size, displaying big eyes, nostrils and large wings with small ears. Microchiroptera (insectivorous bats) are small in size with small eyes and nostrils but large ears.
Microbats are more evolved from old world bats; during evolution they developed echolocation as a sixth sense, allowing them to perceive far beyond the ordinary sense organs. They can detect any object in darkness with help of echolocation. They emit ultrasonic waves with the help of specialized tissue systems. They may contract their larynx or click their tongues, producing sounds of ultrasonic frequency ranging between 20 to 200 kHz, depending on the species. They receive the echoes by means of external adaptations. These are present in the form of a large variety of sizes, shapes, folds and wrinkles throughout the body which funnel the echoes and sounds emitted from prey. The bats can thus gauge their distance from any object.
Bats are not particularly social creatures, however they exhibit colonial roosting, a unique feature of bats, which protects them from predators. Size, shape and site of roost vary from species to species. Large species of bat like Pteropus g. gigentieus always prefer trees as roost sites, whereas most microbats choose caves, old buildings and hollow tree trunks as roosts.
The Thar Desert has always flourished on a deep, understanding and respectful relationship between human and wildlife. Although kings would hunt for entertainment, religion would intervene, bringing forth a conservation motive, and give priority to wildlife conservation. Bishnoi religion is one such example. Guru Jambeshwar Bhagwan was the founder of Bishnoi religion. The Bishnoi people have been following the teachings of Guru Jambeshwar Bhagwan to protect wildlife.
The bats, in this community especially, play an important role in the maintenance of ecological systems. They feed on thousands of insects in one night alone, protecting crops and providing free and chemical free pesticide action! Their excreta, which can be found in roosts site like caves is collected and used as a natural fertilizer, Guano. It is rich in potassium and magnesium and helpful in the agricultural industry as organic manure. They are great pollinators who help in seed dispersal. Birds, many plants species, more than 132 genera depend on bats because they are capable of scattering seeds 50km away from the trees.
This animal kingdom group, which has lived in congruity with human beings, is now considered evil and dangerous. Ancient ruins of palaces of kings and old and abandoned houses are their primary roosting areas. The fears and superstitions that surround bats probably developed due to some people who visit these dark places like caves and old houses where thousands of bats live in groups. They shine flashlights and talk loudly, releasing a hazy swarm of bats from their clusters, usually petrifying the visitors.
On the other hand, there are also people whose lives depend on bats. They collect the aforementioned Guano and sell it in the market as fertilizer, which is a very essential component for the cultivation of the local chilli in Rajasthan. These chillis are vital to the diet of Rajasthani people, as it assists in digestion and metabolism of food in the dry and arid climate.
It is sad to report that in recent years, due to climate change and environmental disturbance, some species of bats have become locally extinct. People are breaking down old houses to build new homes. So also, old palaces and monuments are being renovated to increase tourist traffic and of course, there is the omnipresent threat of deforestation which eradicates not just their roost sites, but their food sources as well.
We need to understand that every creature is integral and irreplaceable in the web of life. Bats, however scary and demonic they may appear to some, are actually pivotal for the survival of many species, including humans. It is important to study and comprehend their behaviour and habitat requirements so that, in the process of urbanizing the planet, we do not eradicate this gem of a species.
(The original post can be accessed here.)