Extensive mining of coal and limestone in various pockets of Meghalaya in North East threatens to take toll on the caves in the region and consequently their occupants majorly bats, many of which are from highly protected species, a team of researchers has warned.
Meghalaya harbours 67 species of bats, the highest number of chiropteran species among all Indian states.
“The abundance of underground shelters has been suggested to be the prime reason for high bat diversity in Meghalaya . Although it is difficult to establish the level of dependency of bats on caves, at least 37 out of 67 reported species in Meghalaya are known to inhabit caves, at least temporarily . Some of the globally threatened, data deficient or rare bat species have been recorded from the caves of Meghalaya.
These include Wroughton’s free-tailed bat, a highly protected species under Indian laws and of which Meghalaya holds about 50% of the known global population; tail-less leaf-nosed bat, great evening bat, Rickett’s big-footed bat, Burmese whiskered bat among others, as per the scientists.
Besides, many of the caves harbour large populations of bats like Eonycteris spelaea, Miniopterus magnater and several species of Rhinolophus and Hipposideros. From an ecological point of view also, bats are crucial for maintaining the subterranean biodiversity, as bat guano is an important source of energy in these energy impoverished ecosystems. Many guanophilic beetles, cockroaches, mites, crickets and molluscs thrive on bat excreta, which in turn serve as prey for other predators.
“By virtue of rich limestone deposits, especially in the southern fringe of the Meghalaya plateau and high average annual precipitation, the state also supports numerous caves and caverns, some of which are among the largest and most complex in the Indian subcontinent,” noted the researchers in their study, “Caves as priority areas for the conservation of lesser known mammalian fauna in Meghalaya, North East India.” It is published in the journal Current Science.
The researchers are Uttam Saikia from Zoological Survey of India (North Eastern Regional Centre, Shillong), Brian Kharpran Daly from Meghalaya Adventure Association, Shillong and Manuel Rued, Department of Mammalogy and Ornithology, Natural History Museum of Geneva, Geneva.
“Although about 1000 caves in the state have been explored and mapped, they have not been examined biospeleologically and not much is known about the biota living in these caves.
“Unless the biological values of these caves are documented, conservation prioritization is difficult. Secondly, there has been extensive mining of coal and limestone in the karstic areas of Meghalaya for a long time. This has resulted in a number of serious ecological problems like deterioration of water quality, diminishing plant cover, loss of aquatic biodiversity, degradation of soil productivity, etc.
“In several instances, cave systems have been physically damaged or wiped out of their biota,” they said, citing instances of Krem Umlawan, part of the mammoth UmlawanKotsati cave system in the East Jaintia Hills of Meghalaya. “It is now devoid of any original biota because of sludge deposits from limestone mining in nearby areas. Likewise, Krem Mawmluh in the East Khasi Hills, a UNESCO geological heritage site of the state, witnessed a portion of a cave ceiling collapsing due to limestone mining in the nearby areas,” they said.
