Browsing by Author "Bhatnagar, Yashveer"

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Exploring ecological separation between Himalayan blue sheep and Himalayan ibex during winter in Indian Trans-Himalaya
(Wildlife Institute of India, Dehradun, 2024) Prakruthi, G.M.; Sathyakumar, S.; Lyngdoh, Salvador; Bhatnagar, Yashveer
According to resource selection theory, two related species with similar ecological requirements compete for the same resources. They can only coexist if they are ecologically separated, either by habitat or food preference. This study explored the resource use and ecological separation of ibex (Capra sibirica himalayanus) and blue sheep (Pseudois nayaur) during the winter in the Spiti Valley, focusing on their segregation in space, habitat use patterns, diet, and activity pattern. The study was conducted in Kibber and Chicham areas (57 km2) of Kibber Wildlife Sanctuary, Himachal Pradesh, India. This study slightly deviates from the findings of a previous study by Namgail (2006), which reveals a high overlap in the habitat use between ibex and blue sheep in the Zanskar mountains. Systematic sampling using transects and trails, vantage points, opportunistic sampling, and camera traps was employed. Habitat and vegetation variables were recorded at random points and animal sightings to understand the patterns of habitat use and food selection. Spatial and temporal overlaps were analysed and micro-histological analysis of faecal samples compared the proportions of monocots and dicots in their diets. The study investigated how ungulates utilize habitats and their dietary habits with the availability of resources in their environment. Results showed substantial overlap in activity patterns, with the Jaccard similarity index indicating less spatial overlap between the species. The generalized linear model and Non-metric dimensional analysis indicated segregation based on their habitat preferences. However, there were no significant differences in their diets, the two species differed in the use of habitat at finer scales. Ibex preferred interspersed rocky slopes and slabs because of high rocky areas (escape terrain) and sparse vegetation, trading food for security. Blue sheep preferred less rocky areas with high vegetation cover like smooth slopes. Ibex preferred areas with more escape routes available than blue sheep. Thus, I conclude that Blue sheep, being more abundant than ibex, occupy distinct regions within the study area, and have a competitive advantage. While ibex are present in smaller numbers and confined to a specific region. Understanding their ecological requirements, especially in harsh winters, is crucial for targeted conservation efforts to ensure the sustainability of these species in a rapidly changing environment. Future research should focus on climate change impacts on habitat use and resource availability
Habitat Preference of Sambar (Cervus unicolor) in Rajaji National Park
(Wildlife Institute of India, Dehradun, 1991) Bhatnagar, Yashveer; Prasad, S.N.
A study on the habitat use by sambar in the Rajaji National Park was carried out from November 1990 to April 1991. Data was collected on the vegetation, habitat use and abundance of sambar. Habitat preferences were studied using the utilization availability technique and animal abundances using the King census method. The major results regarding vegetation studies were: 1. Nine vegetation types (VT) were recognized in the study area based on their broad association and physiognomy as: the plains sal forests (SF), plains mixed forest plantation (MFP), mixed forests (MF), mixed forest, riverain (MFR), mixed forests slope (MFS), mixed forest shady valley (MFSV), mixed forest grassy slopes (MFSG), mixed forest slope with sal (MFSS) and sal forest slope (SFS). 2. The dominant tree, shrub and grass species and their abundances for each VT are presented. 3. The hills on the whole had a greater proportion of palatable tree species with branches accessible to sambar. They also had a greater diversity of forage and cover providing shrubs. The major results of the preference analysis were: 1. Sambar shows preference for MFS during both seasons (November to Mid February-winter and Mid February to April-Spring/summer).2. Low to moderate tree and shrub covers are preferred during both seasons. Higher grass cover categories are preferred by sambar during both seasons. 3. Lopped areas show avoidance mainly during summers. The major results of the sambar abundance were: 1. Sambar density for the 10 transects, representing hills and plains and varied levels of disturbance are presented.2. Sambar density during both seasons was higher in the hills.3. The sambar density does not significantly vary between the hill, disturbed and hill relatively undisturbed transects during both the seasons.
Interactions Between Livestock and Ladakh Urial (Ovis vignei vigei)
(Wildlife Institute of India, Dehradun, 2003) Raghavan, Bindu; Bhatnagar, Yashveer; Qureshi, Qamar
The Ladakh urial is a highly endangered and endemic subspecies of wild sheep. Past hunting pressures had decimated the population to extremely low levels. Recent estimates (1,000-1,500 individuals) suggest a marginal increase in numbers. The Ladakh urial occupies plateaus and gentle slopes along the lowermost elevations in the Indus and Shyok Valleys, areas that are easily accessible and heavily used by humans. This is also the most heavily populated area and due to geopolitical reasons, receives the highest developmental benefits. Due to such changes the Ladakh urial may be highly vulnerable to population decimation. Pastoralism is a way of life in bulk of the Ladakh Trans-Himalaya; a region Where wildlife including endangered species such as the urial and snow leopard are not restricted inside wildlife Protected Areas alone. Such species thus share their habitat with the over 3,00,000 livestock that occurs in the region. Recent studies from the Trans Himalaya have indicated competition with livestock as an important reason for the decimation of wild herbivore populations. This study thus aimed to investigate the interactions between the endangered Ladakh urial and livestock during the winter of 2002-03, a season of resource scarcity. We investigated the habitat selection of the Ladakh urial and its separation with livestock at the level of space, habitat variables and diet, to gather evidence for competition. Four trails were walked 10 times each to obtain information on the habitat usage by the urial and livestock. Further information on livestock use was gathered from the herders using semi-structured interviews and resource maps. Diet of both urial and livestock was investigated by examining recently foraged sites using 10, 1 mX1 m quadrats at each such site. All sightings from the trails were plotted on a 1 :50,000 501 Toposheet. A 500mX500m grid was overlaid on these locations to obtain the grids used exclusively by the urial and livestock and by both together to calculate spatial separation. Both, Ladakh urial and livestock primarily used the mid elevation zones (4,121- 4,400m) with gentle to moderate inclination (<30°). However, along the elevation gradient there was some separation in that the urial used the uppermost elevations to a substantial degree (44%) even during the cold winter season, which livestock avoided.The findings of this study thus show that the habitat and diet requirements of Ladakh urial and livestock sharing the range were similar during the winter season. The relatively high use of the sparsely vegetated uppermost elevations of the range by urial, where the cost of foraging is likely to be higher than the mid-elevations suggests that the urial were excluded from these areas by the livestock. We also reason that the relatively poor young:100 adult female ratio (31:100) may be a manifestation of the stress provided by such competition with livestock and survival in sub-optimal habitats.
Ranging and Habitat Utilization by the Himalayan Ibex (Capra ibex sibirica) in Pin Valley National Park.
(Wildlife Institute of India, Dehradun, 1997) Bhatnagar, Yashveer; Rawat, G.S.
The Himalayan ibex is an important prey species of the endangered apex predator of the alpine region, the snow leopard (Schaller 1977). There is an imminent threat to the trans-Himalayan areas in India due to increasing human activities. In this context the study is conducted to study ibex in a relatively safe population to learn about its habitat requirements and ranging behaviour. The study area is part of the Pin Valley National Park (PVNP; 31o 6' 40'' to 32o 2' 20'' N latitude and 77o 41' 21" to 78o 6' 19" E longitude), located in the South-East of the Lahul and Spiti district of Himachal Pradesh