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Every species has the right to live irrespective of how small or how different they might be. Thinking of mammals, one always finds themselves having thoughts about the charismatic species, rarely does a person wonder about small creatures like bats. Bats being the second largest groups (in numbers) in the section of mammals require the most attention. They are in the minority when people think about conservation or protection. Many myths go about them, the most common one being “bats are blood sucking creatures which may transform themselves into mystical legends known as Vampires in the night”. Due to myths like these, people have misconceptions about bats and do not understand the contribution of bats to the environment hence being indifferent or scared towards the presence/absence of bats.
Perceived as carriers of disease and “flying rats,” these creatures are the most undervalued animals. They roost in secluded places hanging upside down as a rest form. The valves in the arteries are designed to be a one-way flow which prevents the blood from flowing backward. This mechanism protects the bat’s brain from being flooded by blood, thus enabling them to hang upside down. Bats have special tendons in their legs connecting the claws to the upper body. The claws can be activated only when the muscles are activated. So when a bat sleeps the claws still cling on due to the weight of the body even though the muscles are relaxed. When the bats want to release themselves from the perch, then they activate the tendons through muscles to release the grip. Some bats may even go into torpor, a state of hypothermia which may last from a few hours to a few months; a condition adapted for the survival of winter season.
Bats are the only mammals that can fly over long distances. Approximately 1140 species of Bats exist globally making up one-fifth of the mammal population on Earth according to Bat Conservation International (BCI). Even though they are found all over the world, no records of bats have been seen from the Arctic, Antarctic, and few remote oceanic islands. The greatest diversity of bats exists in the tropics with Indonesia having 219 species of bats and Central and South America being home to almost one-third of the world’s bats species. As per the IUCN Red list Category 2016, 4 species of bats have been put in the Extinct (EX) and Extinct in the Wild (EW) Categories. Additionally 70 species are classified as Critically Endangered (CE) and Endangered (EN) and about 101 species are classified as Vulnerable (VU) species. In the lower risk categories, the combination of Least Concern (LC) and Near Threatened (NT) categories give out Seven hundred and seventy-four species in total.
South Asia has about 123 species of bats of the world’s total bat species with India having the maximum number. With India’s population reaching a new height every millennium, the future of conservation biology- India’s bats, in general, has started seeming bleak. Hope can only be seen through the people, the NGOs, the small activist groups and via preservation of natural habitats.
With each of the states of India having its share of peculiarities of climate, topography, flora and fauna’ the state wise review of bats shows that West Bengal has the highest number of bat species reported till date, consisting of about 54.72% of the entire bat species of India. The North Indian plains have 71 species of bats feeding on insects (insectivorous), of the 14 species of the bats feeding on fruits (frugivorous) half are reported from the North-East region as well as from the islands. Meghalaya has a considerably large aggregation of bat species, and with the Central and South-West region of India, the most explored; about 779 localities are reported for 50 bat species. This knowledge helps to understand the preferred ways of various bat species for the climate, topography, and vegetation in India.
India’s bat fauna
In the recent studies, bat fauna in India has been found from Western Ghats mainly Kudremukh National Park, parts of Marathwada (especially Aurangabad and Nanded districts) region of Maharashtra but unexpected recordings have also been found from Delhi, Himachal Pradesh , IISc Campus, Bengaluru and Mysore city. Maximum studies have been done on the Indian species Indian Flying Fox (Pteropus giganteus) for conservation strategies. Studies conducted in the Kacharighat Roosting site of Dhubri site of Assam showed that the numbers of the bat species Pteropus giganteus reduced from 547 in January 2001 to 287 in January 2010. In other researches done on conserving the Indian flying fox bat, local people were involved in sustaining the roost site at Madhukaatu Kali sacred groove, Tamil Nadu with 431 bats counted from two main trees Acacia leucophloea and Pogamia pinnata. The bats were able to stay peacefully as they were believed to be devoted to deity Kali. Some researches were also undertaken on Pteropodid bats in general in and around Uttar Pradesh state as well as Tirunelveli, Tuticorin and Kanyakumari Districts of Tamilnadu.
Apart from Indian flying fox, few other species found in India have been closely studied. These include Indian Fulvous Fruit Bat (Rousettus leschenaultia), Greater/ short- nosed Fruit Bat (Cynopterus sphinx), Greater Mouse Tailed Bat (Rhinopoma microphyllum), Long Winged Tomb Bat (Taphozous longimanus), False Vampire Bat (Megaderma lyra) and Salim Ali’s fruit bat (Latidens salimalii) among others.
The Indian flying fox bat, the largest bat species of India is found in many states. Although its status falls under Least Concern (LC), yet it’s numbers are seen fast decreasing as they are hunted and their habitat is destroyed on a large scale. Generally considered as vermin due to its nature of feeding on fruit farms, this species is far more valuable when looked at from the pollinator and seed dispersal side. Not only are they important as pollinators, but they are useful in treating specific diseases such as rheumatism, asthma, chest pain and fever with chills due to which they are over exploited.
After the Indian flying fox, the other most commonly studied bat species is the Salim Ali’s Fruit Bat. A cave dwelling bat extremely sensitive to disturbance, this species is very hard to find. It’s general habitat includes coffee plantation and montane evergreen forests. This species has now entered the Endangered category (EN) with its major threat being hunting. The villagers hunt these bats for traditional medicine. The other threats include disturbance to roost sites by humans and hunting for extraction of oil for curing asthma. Tree cutting is also a major threat to this species. Not much work has been done on its morphology due to its rare sighting and sensitivity to noise.
Despite the fact that only a few species have been studied in detail, the outcome comes down to all bat species facing the same threats in India and other parts of the world.
The main threat to bats being humans, everything just puts itself under that; From danger to roost sites, use of pesticides causing a great decline in bat species, to being categorized as vermin by the Government of India.
Some organizations like Bat Conservation International, World Conservation Union (IUCN) and Zoo Outreach Organization (ZOO) have been trying to make amends realizing the importance of this species. Two decades had passed with work going on to remove bats from the Vermin category from the Wildlife Act (Schedule V) with some relief sought when two bat species were added to Schedule I which mandates the greatest protection. The mysterious and mythological blood sucking creatures of the dark have finally started being defended with campaigns being launched, the release of Bats of India publication and upholding of exhibitions for Bats.
Being the primary predators of night insects, they are very crucial to the environment. They are under severe threat in parts of India. Studies have been undertaken which show that collision of bats with moving blades, tower and associated infrastructure result in their death which is non-compensatory. The disturbance as well as a change in habitat for bats due to the addition of wind mills has detrimental effects on the adversity of bat species. Bats have seen becoming disoriented due to the emission of ultrasonic noise. Another threat remains is to their roosting sites. Some roosting sites are destroyed for construction and development project purposes while others are destroyed by tribes for leisure or through forest fires. The most recent threat to these little creatures is being killed due to fear in humans for spread of diseases like Nipah virus and White-nose syndrome.
In 1987, BCI Scientific Advisor M.K. Chandrashekaran in collaboration with BCI Founder Merlin Tuttle stopped the destruction of vital bat caves in Samanar Hill in Southern India. Most of the threats are seen as a decrease in foraging areas, reduction of prey populations and bats living near human habitations.
What more can be done?
- Protection from climate crisis: Climate crisis being the most talked about topic in today’s world has excruciating effects on bats. Changes in the temperature effects hibernation time meaning that bats are seen emerging early from their long sleep. Another effect which is seen is the change in breeding successes of female bats due to changes in prey availability specially the time of year of year when insects are abundant.
- Prioritizing bats: Bats have taken a backseat when it comes to mammals, which should not be the case as bats are important ecological keystone species which help in pollination, seed-dispersing and even act as pest control agents.
- Research Gap: When bats were put under vermin category some studies were started on these species yet much information is still lacking in most aspects of life of bats.
- Public awareness: People are just not aware about the reality of bats because of which they are the first ones to be ignored when it comes to conserving any species.
Why are bats important?
Bats are the key components of an ecosystem. They act as pollinators, help in seed dispersal, and also control pests.
Frugivorous bats forage long distances for the search of fresh fruit. Since they are small in size they are even able to go through areas where no other species can move about. All this facilitate long distance seed dispersal even from natural to degraded land. Similar is the case of bats feeding on nectar, acting as pollinating agents for the big flowers which cannot be pollinated by insects. The best pest controlling agents being the insectivorous bats whose survival is basically on insects. They can feed on insects which may be three times their body weight.
Another peculiar feature about bats is their echolocation which is very similar to sonar. They make echolocation calls as they fly and then listen and understand the returning echoes to build up a map of their surroundings. Echolocation calls emitted by a bat is a high-frequency system by which transmission of ultrasonic sounds helps them in detecting whether the objects near them including insect prey are for catching purpose or avoiding purpose.
Bats can also be captured as ideal bioindicators of human-induced climate change and habitat quality. Indicators are responses shown to a range of trophic levels representing the impacts of ecological stresses on particular ecological processes, thus being said bats can be listed as ideal bioindicators. Along with being the seed dispersers, pollinators and pest control agents, they are also sensitive to environmental stressors to which they respond in a particular way.
This being said, Bats are not creepy night flyers but have much more environmental conservers in them than we give them credit for.
The key pressing issue related to the conservation of bats is lack of information. Not a lot of people want to undertake studies on these little beings even though research is now advancing on their general distribution and habitat (which is totally not okay!) but what we as commoners can do is that not treat them as vermin and/or shoo them away and/or kill them rather just let them be (they really wont hurt you if you don’t poke them, trust me I know) and also tell people around you not to harm them.
P.S. Hopefully, I may have changed your mind a tiny bit about these creatures. So, for those of you scared of bugs or bees (like me!!), these little creatures are actually a sight for sore eyes.
*This blog post is a part of my research work of Forest Research Institute (Deemed to be) University done under the guidance of Dr. Lalit Sharma. Dr. Lalit is currently one, New Delhi as Assistant Inspector General of Forests. **
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I now write on Green Lens. For more blog posts, please visit there.