Estimation of Population Trend of Seven Endangered Species of Animals in West Bengal

West Bengal is such a state that has been richly endowed by nature in terms of great diversity of physical environment. From Bay of Bengal to the snow-capped Himalaya through vast stretches of alluvial plains, the physiognomic diversity and a myriad of climatic situations have given rise to countless habitats across the Length and breadth of the state. West Bengal falls in the transition zone between peninsular Indian subregion, Indo-Malayan subregion of 0rientaI zone and Palaearctic region. These two rare attributes combined together provided West Bengal its great array of natural ecosystems embellished with the ingress, colonization and interspersion of life forms from all the adjoining regions.

On the other hand, owing to favourable agro-climatic condition, West Bengal was always one of the most populated region of the country (population standing 204 per sq.km. as per census 2001) and the population is ever increasing. The pressure of such an enlarge and impoverished population along with the urbanization and industrial development have taken a heavy toll of natural area of the state through shrinkage and degradation. As a result, many ecosystems and floral-faunal species have become threatened. Unfortunately, while some of the flagship species, have brought under regular monitoring programme as regard habitats and population size, many other equally important as well as threatened species are left uncared for. The present project has been taken to estimate the trend of population, area of concentration and other related aspects of seven such species of vertebrates in West Bengal.

Funded By: Ministry of Environment and Forests (MoEF), Govt. of India
Project Duration: 1991 (1 year)

A) To estimate the population trends of the seven threatened and poorly known species of wildlife in West Bengal and to identify the areas of concentration. The species are-

1) The Himalayan Newt or Salamander (Tylototriton verrucosus).

2) Estuarine or salt water crocodile (Crocodylus porosus).

3) Olive Ridley Turtle (Lepidochelys olivacea)

4) Bengal Florican (Houbaropsis bengalensis)

5) Gangetic Dolphin (Platanista gangetica)

6) Indian Wolf (Canis lupus pallipes)

7) Indian Pangolin (Manis crassicaudata).

B) To review the utilization of funds provided by the Ministry of Environment and Forests, New Delhi for wildlife management such as developing glades, water holes, salt licks, maintaining fire Lines as well as research and awareness programme in the state.

A) Observation was made on the various conservation and management programmes adopted by State Government and it was found that measures were taken in the following sectors-

1) Habitat management

2) Mitigation of man-animal conflict

3) Nature interpretation centre, breeding and Rescue camps

B) From one year field study and information as gathered, following inference was drawn-

1) Population of Himalayan Salamander has drastically gone down or even wiped out from many of its erstwhile habitats in Darjeeling district. However, within a particular range of elevation, the species is still fairly abundant in and around the seasonal or perennial water bodies of very small to large sizes.

2) Seasonal migration of Olive Ridley Turtle for nesting in the coastal zone of West Bengal is a fairly old phenomenon. Various factors responsible for the decline in the population or disturbance in nesting are still operating.

3) From the frequency of sightings of estuarine crocodile in the river systems of Sunderban and the increased incidence of their attack on human beings, it may be derived that the population of them is now fairly established.

4) Occasional reports of sightings of Bengal Florican in the recent past from different parts of North Bengal are available. However, during block count in different sample plots located mostly in the area of its recent sightings could not find any specimen. It is to be noted that vast stretch of riverine grassland, the ideal habitats for Bengal Florican, are still widely distributed particularly in the Buxa Tiger Reserve, Jaldapara Wildlife Sanctuary and Gorumara National Park. Most of these habitats are practically free from any hunting or other anthropogenic pressures. As such there is no apparent reason of non-existence of this bird in North Bengal.

5) It appears that present population of Indian wolf in the state is actually dispersed from neighbouring states of Jharkhand and probably Orissa and found an alternative refuge in the newly grown forested areas in West Bengal. However, population of natural prey species of wolf has not yet been developed in the forest. Present populations of wolf though found shelter in the forest but depend mainly on the domestic stock for subsistence resulting apathy and man-wolf conflict.

6) Systematic survey detected only three specimens of Indian Pangolin in the state. So, no estimate about the density of the species could be made. However, analysis of the sighting, records during last few years by different sections of people as well as indirect evidence obtained during present surveys indicate its extent of occurrence and area of occupancy in the state as fairly high being more than 20,000 sq. km and 2000 sq . km. respectively. It was noted that no specific programme or care has been developed to protect this unique creature in the state.

7) During the surveys, surfacing of Dolphin was frequently observed in the river system of Sunderban. All the specimens which surfaced near the boat were identified as Irrawady Dolphins. It appears that if the Gangetic Dolphin at all occurs in Sunderban, then the population should be considered as few, while the other Dolphin species i.e. Irawaddy Dolphin is the most predominant.

8) Another observation made was that, the number of forest staff assigned for performing activities to protect wildlife and its habitat, is far below the optimum. Often they are not property equipped to fight against the poachers, timber smugglers as well as terrorist activities in the forest.