(Everest) National Park, Nepal?
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Have snow leopards made a comeback to the Everest region of Nepal? Progress report for the International Snow Leopard Trust by Som B. Ale, UIC, Chicago, USA (Photo: S. B. Ale) February 2005 Contents: Introduction........................................................................................................................ 3 Results................................................................................................................................. 4 Discussion........................................................................................................................... 8 References ........................................................................................................................ 13 Executive summary In the 1960s, the endangered snow leopard was locally extirpated from the Sagarmatha (Mt. Everest) region of Nepal. In this Sherpa-inhabited high Himalaya, the flourishing tourism since the ascent of Mt Everest in 1953, has caused both prosperity and adverse impacts, the concern that catalyzed the establishment of Mt. Everest National Park in the region in 1976. In the late 1980s, there were reports that some transient snow leopards may have visited the area from adjoining Tibet, but no biological surveys exist to confirm the status of the cats and their prey. Have snow leopards finally returned to the top of the world? Exploring this question was the main purpose of this research project. We systematically walked altogether 24 sign transects covering over 13 km in length in three valleys, i.e. Namche, Phortse and Gokyo, of the park, and counted several snow leopard signs. The results indicated that snow leopards have made a comeback in the park in response to decades of protective measures, the virtual cessation of hunting and the recovery of the Himalayan tahr which is snow leopard’s prey. The average sign density (4.2 signs/km and 2.5 sign sites/km) was comparable to that reported from other parts of the cats’ range in the Himalaya. On this basis, we estimated the cat density in the Everest region between 1 to 3 cats per 100 sq km, a figure that was supported by different sets of pugmarks and actual sightings of snow leopards in the 60 km2 sample survey area. In the study area, tahr population had a low reproductive rate (e.g. kids-to-females ratio, 0.1, in Namche). Since predators can influence the size and the structure of prey species populations through mortality and through non-lethal effects or predation risk, snow leopards could have been the cause of the population dynamics of tahr in Sagarmtha, but this study could not confirm this speculation for which further probing may be required. 2 Introduction In the early 1970s in east Nepal, the endangered snow leopard Uncia uncia was locally extirpated in what is now Sagarmatha (Mt. Everest) National Park (E 860 30' 53" to E 860 99' 08" and N 270 46' 19" to N 270 6' 45"; area 1,148 km2; figure 1). In 1987, Ahlborn and Jackson (1987) reported some signs probably made by transient cats from Tibet in the Gokyo area of the park. After almost three decades of effective protection measures, the virtual cessation of hunting and the recovery of the endangered Himalayan tahr Hemitragus jemlahicus (and musk deer Moschus chrysogaster) in the park since its establishment in 1976, snow leopards seem to have made a comeback to the world’s highest national park. The Sagarmatha National Park (or Khumbu) lies in the Solu-Khumbu district of the northeastern region of Nepal and encompasses the upper catchment of the Dudh Kosi River system. One of the objectives of this research project is to assess whether snow leopards have established resident populations in the park. How far have they expanded their range? What is the status of their main prey? Answering these questions will be the main purpose of the project (part I). Achieving this will form the basis to explore some ecological questions associated with the larger project on the snow leopard and the Himalayan tahr in Sagarmatha (part II). For management purposes, information on local megafauna such as the snow leopard is crucial not only for the overall management of the park, but also to expedite the trans-boundary landscape conservation, an effort that is currently being undertaken in Nepal and its neighboring countries. Because no protected areas in Nepal are large enough to contain viable populations of snow leopards and other large predators, the establishment of trans-frontier conservation areas at landscape level with neighboring countries may facilitate genetic exchanges between individuals ensuring their long-term survival (Soule 1987, Jackson and Ahlborn 1990, Green 1994). Qomolongma Nature Preserve (Tibet, China), and Langtang, Makalu-Barun and Everest National Parks in Nepal form the largest trans-frontier conservation area covering approx. 40,000 km2 in the Himalayan region. Here we have summarized some findings of part I, with a note on issues akin to local landuse practices that may have relevance to wildlife conservation. A detailed (technical) report will be submitted later. We have also estimated the relative abundance of snow leopards although this assessment is preliminary, and is subject to changes as more information will be collected in coming years. Snow leopards leave marks in the form of scrapes, scent sprays, feces and pugmarks (Rieger 1978, Ahlborn and Jackson 1988) which can be indexed to derive information on abundance using standardized methodology called the Snow Leopard Information Management System (SLIMS) (Jackson and Hunter 1996, see also Connor et al. 1983, Van Dyke et al. 1986, for other species). Sign surveys were conducted in three valleys using SLIMS in habitats with high vs. low human activity (Namche, Phortse and Gokyo). Transect routes were plotted on available 1:50,000 topo maps, most being along landforms where snow leopard sign is likely to be found, such as ridgelines and cliff edges. To minimize within-transect variability, transects were short and rarely crossed habitat (i.e. forest, shrubland, scrubland and grassland) boundaries. Transects were walked by a pair of observers and all sign recorded as to type and number. At each site where snow leopard sign was found, habitat attributes within a 20 3 m radius were determined including elevation, slope, aspect, vegetative cover, dominant topographic feature, landform ruggedness, and land use. Of these attributes, landform ruggedness was the most subjective which included rolling, broken, very-broken, and cliff. Cliffs in this case were defined as being surfaces of 500 or steeper over an area of at least 100 m2 (McCarthy 2000). On each transect a number of random sites (at least one per 100 m) were selected and all habitat attributes were recorded to allow comparisons with sign sites (cf. McCarthy 2000). The attributes of sign sites and random sites were used to compare use and availability. The frequency with which leopards used sites of various habitat attributes was compared to the availability of such sites using a Chi-square goodness-of-fit test. Sign placement was considered an indicator of habitat use by leopards. Sign density, expressed in sign/km of transect was calculated for each transect, for each survey area, and for the whole area. To test for differences in mean density of sign sites between valleys, Kruskal-Wallis one-way analysis of variance was employed. For Himalayan tahr, fixed-point counts from ridgeline vantage points were conducted using the methods detailed by Jackson and Hunter (1996). Survey blocks were outlined on maps and observation sites identified. Each block was scanned and all tahr counted and assigned to sex and age class when possible (see Schaller 1977). Opportunistic observations on tahr and other prey species of snow leopards were also made along snow leopard sign transects which provided supplemental data to fixed-point counts of tahr. A sample of 20 adult males was darted, weighted, aged, eartagged, and their blood samples were collected, as part of the Ev-K2-CNR project. A study on Himalayan tahr was carried out with the following expected results: minimum population distribution, size and density of tahr in selected areas of the park, assessment of sex ratio and assessment of reproductive rate. Observations on the foraging behavior of tahr were also made, and findings will be reported later in the final report. Local herders and key residents were interviewed about wildlife numbers and abundance. They were also questioned on landuse practices such as grazing. 4 Results Between October and November 2004, sign surveys were conducted in three valleys (figure 2-5). Altogether, 24 transects were walked covering 13.4 km in length. Thirty three (10 relic and 23 non-relic) snow leopard sign sites and 56 signs were counted (table 1). No relic signs were discovered in Gokyo valley, but in Phortse and Namche. Scrapes (59%) were by far the most common sign type, which together with feces (32%) constituted over 90% of signs encountered (table 2). Table 1: Site and sign density Location Transect (km) Sign sites Mean site/km Sign (all) Mean sign/km Scrapes Mean scrape/km Phortse 5 25 4.77 43 8.20 26 4.96 Gokyo 5 5 1.10 6 1.32 6 1.32 Namche 4 3 0.84 7 1.95 1 0.28 Total 13 33 2.46 56 4.18 33 2.46 Table 2: Signs encountered in three valleys Block/valley Scrape Feces Hair Scent markPugmark Phortse 26 14 0 1 2 Gokyo 6 0 0 0 0 Namche 1 4 1 1 0 Total 33 18 1 2 2 Total 58.93 32.14 1.79 3.57 3.57 Snow leopard sign density/km of transect was not equal across valleys (table 1). Phortse valley had a higher mean density of snow leopard sign site/km of transect when compared to Namche and Gokyo (F=5.64, df=2, p=0.011). More statistical analysis will eventually carried out in 2005 and 2006, when more data will be collected. Variation in mean sign density between summer and winter may be expected. Sign sites were not found in habitats of varying in features in proportion to occurrence, except in case of vegetation cover (table 3).