16-Jan-2019: Small Woodbrown butterfly rediscovered in Sikkim after 120 years
This year has been an important one for butterfly researchers of Sikkim. After a span of 120 long years, researchers at the Sikkim University in Gangtok have rediscovered the Small Woodbrown butterfly species from Bakhim in Khanchendzonga National Park.
This finding has opened the possibility of occurrence of more species of butterflies that await rediscovery or discovery in the state, which is one of the 36 biodiversity hotspots of the world.
The Small Woodbrown butterfly was discovered in Sikkim in 1887 by a scientist named de Nicéville. But at that time, the exact location of its occurrence and photographic evidence were not presented. This year they have rediscovered the Small Woodbrown butterfly by providing photographic evidence and capturing specimens which proves with utmost certainty that this species occurs in Sikkim.
The Small Woodbrown butterfly, scientifically known as Lethe nicetella is named after its brown-coloured wings patched with white round spots. It is amongst the smallest members of the genus Lethe, with wings that are up to 50 millimeters long. The species is endemic to the eastern Himalayas and occurs in forests lying between elevations of 1,800-2,800 metres. Across the world, species of Lethe are found in Sunda Islands, Japan, Siberia, Himalayas and peninsular India. Of the 41 species of Lethe that are found in India, 32 species are reported from Sikkim alone.
Researchers believe that an important reason why the Small Woodbrown butterfly species was not sighted in Sikkim for more than a century is its close resemblance with another species called Lethe sidonis. This species is fairly common in the Khanchendzonga National Park and differs from the Small Woodbrown butterfly in the size and structure of its wings–a feature that needs to be examined very closely by a trained zoologist using magnifying lenses. Although researchers have observed the Small Woodbrown butterfly feeding on faecal matter of cattle and horses, they are yet to perform an in-depth investigation about its life cycle, feeding and mating behaviour in its natural environment.
Butterflies are important components of the natural ecosystem. They help to pollinate flowers—a process which is necessary for plants to produce viable seeds. Also, some species of butterflies feed on plants, some on animal dung, and very few on smaller insects like aphids, making them important links of Nature’s food chain. Butterflies are also used as indicator species—that is, species whose abundance and physical traits are used by scientists to study forest or ecosystem health. It is also important to understand that every organism–no matter what role it plays in the ecosystem–has an equal right to survive on this planet. Since the Small Woodbrown butterfly is found only in forests, their degradation leading to the disappearance of host plants is a key potential threat to its existence.
After this important rediscovery, researchers plan to explore the diversity of butterfly species in other areas of Sikkim namely Teesta and Rangeet valley and adjoining areas in Darjeeling-Kalimpong of West Bengal. We also plan to carry out DNA-based studies to understand differences in the genetic makeup of various species of butterflies found in these areas.
26-Nov-2018: Rare sub-species of hog deer
Indian scientists have discovered an endangered sub-species of hog deer (Axis porcinus annamiticus) in India, earlier believed to be confined to the eastern part of central Thailand.
Researchers at Wildlife Institute of India (WII), Dehradun reported the presence of a small population of hog deer in Keibul Lamjao National Park (KLNP), Manipur. The population genetically resembles A. p. annamiticus. The study indicates that the western limit of hog deer is Manipur; not central Thailand as believed.
Since hog deer is losing habitat in other countries, the genetically distinct and evolutionarily significant population found in KLNP— considered a biodiversity hotspot on the India-Myanmar border—is significant for conservation.
The isolated and low population of wildlife species is always a matter of concern as it affects genetic diversity. Reduced genetic diversity decreases adaptability of various species in changing environment.
Two sub-species of hog deer have been reported from its range. The western race is distributed from Pakistan and the terai grasslands (along the Himalayan foothills, from Punjab to Arunachal Pradesh), while the eastern race of hog deer is found in Thailand, Indo-China, Laos, Cambodia, and Vietnam.
The hog deer or Pada is an endangered species in the IUCN Red List and is protected under Schedule I of the Indian Wild Life (Protection) Act, 1972. The species has lost ground in most of its distribution range. A small and isolated population of under 250 was reported from Cambodia. However, it was widely distributed throughout the Southeast Asian countries at the beginning of the 20th century.
The study was based on the grant provided by Science and Engineering Research Board, Wildlife Institute of India and the Ministry of Environment, Forest and Climate Change.
4-May-2018: New species of Shieldtail snake discovered in Western Ghats.
Scientists have discovered an entirely new species of Shieldtail snake from the Western Ghats in Tamil Nadu, which differs from other members of its group as it has a broader and longer head and more number of scales on its belly.
Scientifically named Uropeltis bhupathyi, the new snake species is presently only known to exist in the Anaikatty hills of Tamil Nadu which is dominated by a deciduous type of vegetation.
At present, there are 45 known species of Shieldtail snakes in the world, of which 30 are endemic to India and 15 to Sri Lanka. The name ‘Shieldtail’ comes from their heavily keeled tails that terminate in disk-like shields or multiple spines in most species. They are small sized snakes, typically 25 to 50 cm in length and live in loose soil among plant roots or under decaying vegetation. They are inoffensive, non-venomous, and easy-to-handle owing to their inability to bite because they have short head and mouth. They come in a variety of colors, mostly dark shades of grayish black/brown and feed on earthworms and arthropods.
Since the snake species is known to occur in a single small locality and there is limited information about its natural history, the authors have categorised it as ‘data deficient’ in the IUCN Red list of threatened species as of now.
The news species faces threats from road traffic, habitat loss, and a possible fungal infection that leads to deformed heads. The soil in the area being exploited by brick manufacturing industries is also threatening their survival. We need to protect its habitat to conserve this species and probably others that are yet to be discovered from this region.
The species has been named in honour of the late Dr. Subramanian Bhupathy (1963–2014) of the Salim Ali Centre for Ornithology and Natural History, in recognition of his contributions to the appreciation and knowledge of the Indian herpetofauna. Dr. Bhupathy was based on the campus where the type series of the new species was collected, and he published on the existence of this population.