The first official record of animal diversity of the Great Nicobar

The Great Nicobar Island is located further south than Kanyakumari and is closer to Myanmar and Sumatra than to the Indian mainland. Over millennia of evolution and isolation, the island has developed its unique biological diversity. The devastating impact of the 2004 Asian Tsunami had an adverse impact on this biodiversity. Even as the island recovers, increasing human activity is causing habitat disturbance that is affecting the numbers of some of the critical species.

The Zoological Survey of India has published the first official record of the animal diversity of the Great Nicobar Island in a book titled Faunal diversity of Great Nicobar Biosphere Reserve.

“This is the first time a holistic account of the animal diversity of the Great Nicobar Biosphere Reserve has been published. This book is going to provide baseline numbers for all future studies in Great Nicobar Island that are going to be conducted by the Zoological Survey of India. We are making this data publicly available to aid other organisations who aim to conserve its unique biodiversity,” said Kailash Chandra, director of the Zoological Survey of India (ZSI).

In this study, done from April 2010 to March 2013 in the Great Nicobar Biosphere Reserve, scientists at the ZSI recorded the animal diversity of this region from both its terrestrial and marine ecosystems. They also evaluated the success of conservation strategies implemented in this area and listed the factors that are putting the biodiversity in this hotspot at risk. The book lists a total of 1767 species of animals found on the island, which represents 23% of the total diversity of Andaman and Nicobar islands. It includes 558 terrestrial and 1209 marine species.

Pankaj Sekhsaria, a scientist at the Department of Humanities and Social Science, Indian Institute of Technology (IIT)-Delhi, and associated with Kalpavriksh, an organisation engaged with research, advocacy and legal issues in the Andaman and Nicobar Islands, welcomes this research initiative by the ZSI. “These islands remain largely unexplored, and there is likely to be much here that is new to science. We need to make people aware of the richness and diversity of this region to gain more support for its protection and conservation,” he said.

The Andaman and Nicobar archipelago

The Andaman and Nicobar group comprising 572 islands is located between the Bay of Bengal and the Andaman Sea in the Indian Ocean. These islands fall in the Indo-Malayan geographical region since they have a continuation with Myanmar in the north and Sumatra in the south. The Nicobar group comprises just 24 of the 572, and Great Nicobar is the largest island within this group.

It is home to only two tribes — the Shompen and the Nicobarese. There are just 219 Shompen left. They live in the dense interior parts of the reserve, and lead a semi-nomadic life, depending on forest resources for survival, shunning the outside world. The Nicobarese are farmers and fisherfolk who live in the coastal areas and are more open to interacting with outsiders.

The 1044 square kilometre Great Nicobar island is an incredible biodiversity hotspot, bestowed with a variety of ecosystems ranging from grasslands, evergreen forests, mangroves, deciduous trees and coral reefs. It is, in fact, part of the Sundaland biodiversity hotspot, one of the four hotspots that India houses (the other three being Western Ghats and Sri Lanka, Eastern Himalaya and Indo-Burma). The island was declared as a Biosphere Reserve in January 1989 by the Indian government and included in the UNESCO Man and Biosphere program in May 2013.

“Great Nicobar Island is the southernmost island of India and one of the unique biodiversity hotspots of the world. There are many endemic and threatened species in this region, and it is important to conserve them because they aren’t found elsewhere,” remarked Chandra, who was the principal investigator of the study.

A mega-diverse island

The book is voluminous at 30 chapters and lists more than 300 species of fish, 139 molluscs like oysters, clams, squid and octopus, about 50 echinoderms like starfish and sea urchins, 25 sponges, 30 soft corals, 30 shrimps, four lobsters, and five sea slugs. It also has details of 34 reptiles, including eight geckos and 25 skinks. The diversity of invertebrates is equally high, with 55 butterfly species, 66 beetles and about 40 species of Orthoptera (locusts, crickets, and grasshoppers). Among the 155 species of moths, three — Vitesa nicobarica, Miltochrista danieli, and Nyctemera nicobarica — are endemic.

“In addition to the endemic bird Nicobar crake that we discovered from Campbell Bay in 2011, we also found a new species of brightly coloured flatworm and one damselfly during this study,” remarked C. Raghunathan, scientist at the ZSI and a co-author of the book.

There are a total of 71 species of birds recorded in this region. Several endemic species such as the Nicobar serpent eagle (Spilornis klossi), Nicobar parakeet (Psittacula caniceps), Nicobar Scops-owl (Otus alius), jungle flycatcher (Cyornis nicobaricus), wood pigeon (Columba palumboides), and the Andaman cuckoo-dove (Macropygia rufipennis) are threatened by increased human settlements and resulting habitat modification. The population of the flightless Nicobar megapode (Megapodius nicobariensis), listed as ‘Endangered’ by the IUCN, has been dwindling.

The need for conservation

Agriculture, tourism, and deforestation due to urban development are adversely affecting the overall flora and fauna of this region, according to this report.

This region is amongst the best sites for nesting turtles, especially for leatherbacks (Dermochelys coriacea), green turtles and hawksbills (Eretmochelys imricata). However, increased sand mining and beach pollution are posing a threat to their breeding sites.

“Improved patrolling on beaches during nesting season and increasing public awareness may help conserve these animals,” Chandra observed.

Of the total of 78 species of crabs recorded in this region, “the population of coconut crab, which is protected under the Wildlife Protection Act is continuously decreasing, and special measures must be initiated to prevent this loss,” warned Chandra.

Several endemic species find a place on the IUCN Red List – the Nicobar flying fox (Pteropus faunulus) is categorised Vulnerable, and the Nicobar tree shrew (Tupaia nicobarica) and Miller’s Nicobar rat (Rattus burrus) are listed as endangered.

The numbers of long-tailed macaque (Macaca fascicularis), the only primate species in this region is also facing threats in areas adjoining human settlements such as farms. Their numbers seem stable as of now but they may be experiencing the brunt of habitat loss, as there are frequent reports of human-macaque conflict, Chandra said. Villagers use domesticated dogs to protect their crops from the macaques. His team reported significant numbers of handicapped and injured adult animals in their survey.

Meera Anna Oommen, associate director of the Dakshin Foundation, agrees that “the long-tailed macaques frequently raid crops on the Great Nicobar Island,” but believes that their numbers are unlikely to be affected in the long run. She visited the Great Nicobar Island trying to habituate a troop as a part of her study. “But they are an aggressive lot and rowdy to boot,” she explained. They are as common and problematic as the bonnet and rhesus monkeys on mainland India, she adds.

[Read: These coconut-eating macaques love to floss their teeth].

According to Chandra, another concern in the Great Nicobar Island is poaching of sea cucumbers and seashells by divers from neighbouring countries in these waters. “Stringent measures to curb this activity need to be implemented to conserve these valuable resources,” he warned.

The 2004 tsunami wiped out 6915 hectares of forestland from the Great Nicobar. The natural mangrove vegetation and coconut plantations have recovered significantly but not completely.

Chandra believes that in addition to listing the animal diversity of the Great Nicobar Island and being a reference manual for scientists, this book will educate citizens, fuel discussions and encourage organisations to take up conservation measures in this region in the future.

CITATION:

Faunal diversity of the Great Nicobar Biosphere Reserve. Edited by Chandra K., Raghunathan C., & Mondal T. (2017). Published by the Zoological Survey of India.