Status and Distribution of Nilgiri Tahr Hemitragus Hylocrius in Kerala Part of the Western Ghats
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FIELD REPORT ZOOS' PRINT JOURNAL 21(9): 2379-2385 STATUS AND DISTRIBUTION OF NILGIRI TAHR HEMITRAGUS HYLOCRIUS IN KERALA PART OF THE WESTERN GHATS Saju K. Abraham 1, P.S. Easa 2 and M. Sivaram 3 1 Sub Inspector of Police, Areacode P.O., Malappuram District, Kerala, India 2 Wildlife Trust of India, A 220, New Friends Colony, New Delhi 110065, India 3 Kerala Forest Research Institute, Peechi, Kerala 680653, India Email: 2 [email protected] (corresponding author) plus web supplement of 2 pages ABSTRACT management options for the species. Madhusudan (1995) and A survey of the threatened and endemic Nilgiri Tahr was Madhusudan and Johnsingh (1998) reported sexual segregation conducted in the Western Ghats in Kerala to identify and habitat choice, respectively. locations of distribution and to assess its status in 2001. This study reveals that the population of tahr in Kerala is highly fragmented. A total of 998 animals were estimated in Fragmented populations of the tahr in its range have been 11 populations. The largest population of 696 individuals reported earlier by Davidar (1978). There have also been was in Eravikulam National Park. The habitat in Varayattu observations and reports of such populations from other parts Mala in Neyyar is extensive and rich in food species, though (Fletcher, 1911; Davidar, 1976, 1978; Daniel, 1987). Schaller the number sighted was low. The Kochu Pamba area in the fringes of the Periyar Tiger Reserve is a promising location (1971), Daniel (1971), Davidar (1963, 1971, 1975, 1976, 1978) and in terms of vastness and lack of disturbance. The areas in GREENS (2000) have given the locations and the size of tahr Nelliampathi Hills are rich in terms of food abundance and populations. Anonymous (1993), Easa and Jayaraman (1998), extent of grasslands. However, human disturbance poses a and Easa et al. (2002) reported the numbers in Eravikulam major threat to these populations. National Park. Easa and Sivaram (2002) reported the status as a part of developing a habitat suitability index for the species. KEYWORDS Distribution, Eravikulam National Park, Hemitragus The Management Plan for Eravikulam National Park gives the hylocrius, Kerala, Nilgiri Tahr, status, Western Ghats details of the population in the Park (Anonymous, 2002). However, there have been no recent efforts to identify and The Nilgiri Tahr Hemitragus hylocrius Ogilby, 1838 is restricted assess the status of the tahr populations in the entire state. to the hills of southern India, at an altitude range of 1100-2695m The present survey was undertaken to locate and assess the (Images 1-4w). The Nilgiri Tahr has a short grey-brown or dark status of fragmented populations of tahr in Kerala and to identify coat. Facial markings are particularly distinct in mature males threats. and consist of a dark brown muzzle separated from a dark cheek by a white stripe running down from the base of horns. It is METHODS listed in Schedule I of the Indian Wildlife (Protection) Act 1972 The published literature was referred for information on and categorized as Endangered by the IUCN (IUCN, 2006). locations of hitherto reported populations and personnel Uncontrolled hunting and conversion of habitat to plantations involved in tahr conservation were consulted to get more recent and other human related pressure have resulted in the decline information on distribution and status in such areas. These of the population (Schaller, 1977; Davidar, 1978). Its habitat areas were thoroughly searched during April-May and August- has been reduced to less than one-tenth of the total range of October, 2001 for the presence of the animal. The details collected the species in the past (Schaller, 1977). include herd size and the age-sex classification suggested by Rice (1984) as given below Information on the habits and biology of the Nigiri Tahr is mostly confined to hunting accounts and description of Young (0-1 years) Light brown coat encounters with the animals. Systematic observation has been Yearling (1-2 years) Grey brown coat Adult Female (2+ years) Grey brown coat, Shoulder height limited to Schaller’s study in 1971. Rice (1984) was the first to above 70cm make an extensive study on the ecology and behaviour of Nilgiri Light brown male (2-4 years) Grey brown coat Tahr. Several papers on the biology and management of Nilgiri Horns thick facial markings distinct Tahr in captivity have also been published (Pillai, 1963; Potti, Dark brown male (5 years) Grey brown coat- dark brown 1966; Chandran, 1980; Wilson, 1980; Swengel & Pichner, 1987). Larger than Adult female Saddle back male (6+ years) Dark brown, Shoulder height 110cm Rice (1988) and Murugan (1997) discussed the population Saddle on the back, white knee patch dynamics and habitat requirements of Nilgiri Tahr in Eravikulam and the Nilgiris in Tamil Nadu, respectively. Rice (1986) and The indirect evidences were also recorded. The latitude and Easa (1995) discussed the prey-predator relations in Eravikulam longitude of the locations, altitude, extent of the area and with particular stress on tahr. Sumitran (1993) studied the number of cliffs were recorded. A qualitative assessment of the ecology of the tahr in the Nilgiris, and Mishra and Johnsingh food species in the area, based on the observations of Rice (1994) compared the habitat and population in Anamalai and W see Images in the web supplement at www.zoosprint.org Parambikulam wildlife sanctuaries. Alembath (2002) discussed © Zoo Outreach Organisation; www.zoosprint.org Manuscript 1517; Received 02 February 2006; Revised received 18 July 2006; Finally accepted 01 August 2006; Date of publication 25 August 2006 September 2006 | ISSN 0973-2535 (Print edition); 0973-2551 (Online edition) 2379 Status and distribution of Nilgiri Tahr in Kerala S.K. Abraham et al. (1984) in Eravikulam, was also made. Information on the Table 1. Group composition of Nilgiri Tahr in various adjacent areas and sources of disturbances was documented. locations other than Eravikulam Location (District) AM AF SAM SAF Y1 To t a l * Bounded count technique proposed by Regier and Robson (1966) was followed to estimate the population in Eravikulam. Elival mala (Palakkad) 2 5 1 3 - 11 Parambikulam (Palakkad) 2 7 2 4 2 17 In this technique, repeated independent efforts are made to Nelliampathi hills (Palakkad) 4 14 6 8 5 38 census the population. In any census, the observers are not Chinnar (Idukki) - 3 - - - 3 likely to detect all the individuals in the area. The construction Meesappuli Mala (Idukki) - - - - - 64 Gundumala (Idukki) - - - - 60 of an estimate of population size is based solely on the numbers Mangaladevi (Idukki) 6 2 4 - 12 observed in repeated incomplete counts. Twelve blocks based Kochupampa (Idukki) 4 7 2 5 4 22 Varayattu Mala (Thiruvananthapuram) 6 - - - 58 on the home range, as suggested by Rice (1984), were taken as Ponmudi hills (Thiruvananthapuram) - - - - - 18 the basic unit for population estimation. The blocks were repeatedly covered on foot for a fixed period recording the Total 303 animals sighted for five days in April and October 2000 and in * Total need not tally across rows because of the unknown age group December 2001 in Eravikulam National Park. composition; AM - Adult Male; AF - Adult Female; SAM - Sub Adult Male; SAF - Sub Adult Female; Y1 - Yearling The unknown population size N was estimated by & 76045'E ). It is one of the smallest hill ranges in the Western ˆ N = X (m) + [X(m) - X (m-1)], Ghats. The peaks - Vellingirimala, Kunjaramala, Peria Kunjaramala, Ayyappanmudi and Elivalmala rise sharply from < < < where X(1) X(2)… X(m-1) X(m) represent the numbers observed the basin reaching heights between 1500 and 2100m. Smaller in consecutive days, arranged in increasing order. grass-covered hills are found in this area. The lower and upper confidence limits of N are Elivalmala lies to the north and west of the Palghat gap and 0 0 NL= X(m) south of Muthikulam (between 10 56.206' & 10 56.103'N and between 76038.267' & 76038.05'E). The extent of the grassland NU = X(m) + [X (m) - X (m-1)] [1-á / á] in Elivalmala area is about 10ha and is bordered by evergreen forests on the northeast and south and rocky cliffs on the Where X(m) and X(m-1) are the largest and second largest counts western side. Eleven animals were seen during the visit. One obtained respectively, á is the type-I error. In this study, á is was a lone saddleback, about 6yr old. A group was sighted fixed as 20 per cent. Useful descriptions of this technique are very near to the cliff and had six adult females, two sub adult found in Seber (1973) and Routledge (1982). males and two sub adult females. They moved away in two groups comprising of six and four. The forest officials of the The Park boundary and the block boundary were visited and Singappara Forest station had observed a herd of 30 in the latitude and longitude of various locations were recorded December 2000. The abundance of tahr pellets clearly indicated using a GPS receiver. A digital map of Eravikulam National Park use of this area by more than one herd. was prepared using GPS data with the help of MapInfo Professional and topo sheets. The area of each block was Another tahr habitat is Kuncharmala, which borders Kerala- calculated and the figures obtained were used to estimate Tamil Nadu in the southern end of the Siruvani dam. It is density in each block. contiguous with the Ayyappanmudi and is about 1km2 in extent. The middle land grassland extends to over 2ha area. A major RESULTS part of the area is steep cliffs. Stunted evergreen forests border STATUS AND DISTRIBUTION the top portion of the hill.