Theses and Dissertations

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Author: search.filters.author.Jhala, Y.V.Subject: search.filters.subject.Prey species

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Now showing 1 - 4 of 4
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    Assessment of landscape patterns for modeling habitat suitability for lions and prey species in Gir Protected Area, Gujarat.
    (Wildlife Institute of India, Dehradun, 2013) Basu, Parabita; Qureshi, Qamar; Jhala, Y.V.
    Conservation of ‘source’ alone may not be a sufficient strategy to ensure long term persistence of lions; rather it is enhanced by maintaining connectivity among different populations so as to permit lion movement across human-dominated areas. However, the traditional land-use patterns within Gir landscape is changing at an alarming rate mainly as a result of agricultural expansion, urbanization and industrialization. In this scenario, I attempt to (1) Examine the distribution of suitable lion habitat in Saurashtra, especially in areas outside of protected area to assess the potential of the landscape for supporting an increasing lion population, (2) Identify functional corridors joining Gir and Girnar protected area with suggested management interventions, necessary for safeguarding the corridor, (3) Evaluate the current landscape architecture of Gir PA and its surroundings (4) Assess the rate of change in land use and vegetation patterns within Gir PA, (5) Develop habitat suitability models at different spatial scales for lions and its principal prey species.
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    Occupancy and abundance of tigers and their prey in Terai Arc Landscape, Nepal.
    (Wildlife Institute of India, Dehradun, 2012) Karki, Jhamak Badur; Jhala, Y.V.; Pandav, Bivash
    The occupancy, distribution and tiger density are important information for management and conservation policy formulation. Realizing this need, this study was undertaken. The major wild prey species of tiger are spotted deer (Axis axis), wild pig (Sus scrofa), sambar (Rucervus unicolor), swamp deer (Rucervus duvaucelli duvaucelli), barking deer (Muntiacus muntjak), hog deer (Heylaphus porcinus) and gaur (Bos gaurus) in Nepal. To evaluate the occupancy of tiger in Nepal's Terai Arc landscape (TAL), sign survey was conducted in 96 grids (area 225 Km2 ) in 14 districts, including PAs. To assess correlation of the tiger occupancy with the availability of wild prey, and the human disturbance with the habitat use by the tiger, the sign of human disturbances (fire, timber cut, fuel wood collection, sign of poaching) and prey presence were recorded during the winter season. To estimate the density of tigers wild prey in PAs of Nepal's TAL, distance sampling was conducted along the predefined line transects during the summer season
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    Feeding ecology and habitat needs of wolves (Canis lupus pallipes) in the Bhal area of Gujarat.
    (Wildlife Institute of India, Dehradun, 2002) Jethva, Bharat D.; Jhala, Y.V.
    Present study was conducted in the Bhal region of Gujarat between 1996-2000 to study the feeding ecology and habitat needs of wolves. Food habits of wolves in the Bhal were studied by analyzing 1246 wolf scats from 5 packs. Standardization of scat analysis technique suggested that minimum of20 hair should be scanned per scat to get complete representation of mammalian prey species in that scat. Minimum number of scats that need to be analyzed per pack were different for different wolf packs (ranging from 165 scats needed for Velavadar National Park (VNP) pack to 40 scats from Mithapur pack and 180 scats for the wolves of entire Bhal) because of different diet diversity. Mammalian prey species dominated in the diet of wolves and 80.5% scats were found with only one prey species. Comparative account on feeding ecology provided in the present study by scat analysis and monitoring of radio-collared wolves suggests that wolves depends primarily on wild prey species (blackbuck being major prey) and predation on domestic livestock results in minimal economic loss to the local people. It emphasizes the importance of protected areas for the conservation of wolves. Use of radio-telemetry in the present study provided critical information on territorial behavior of wolves, their population density, size of home range and their relation with prey abundance, habitat use and the size and characteristics of core areas.
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    Computing Biomass Consumption from Prey Occurrences in Scats of Tropical Felids
    (Wildlife Institute of India, Dehradun, 2013) Chakrabarti, Stotra; Jhala, Y.V.; Qureshi, Qamar
    A robust understanding of prey use and selection by carnivores provides crucial insights into their ecology, conservation and management. In majority of the cases, scat analysis is most effective to assess diet spectrum of carnivores, but require correction for potential biases for estimating biomass contribution of different prey items. Since small prey have higher indigestible matter per unit body mas~ due to higher surface area-to-volume ratio, relative frequencies of prey remains in scats do not represent their consumed biomasses. Thus ~ to accurately estimate the proportions of different prey consumed, it is necessary to develop relationships between biomass consumed per field collectable scat and prey weight through feeding experiments. However, no such relationship exists for felids of the Indian sub-continent. The studies on diet of big cats like lion (Panthera leo), tiger (Panthera tigris) and leopard (Panthera pardus) have used a similar relationship based on cougars (Puma concolor) by Ackerman et al. 1984 owing to the unavailability of any species specific relations. Methods: A series of feeding trials were used on Asiatic lion (Panthera leo persica), leopard and jungle cat (Felis chaus) to develop prey incidence to biomass conversion equations (hereafter mentioned as biomass models or biomass equations). Principal findings: All the models showed satiating relationships between biomass consumed per collectable scat and prey weight given by asymptotic exponential functions. However, carnivore specific models when scaled to their respective body weights did not differ significantly between each other, allowing derivation of a generalized biomass model for tropical felids. Inferences using present study models refined existing representation of diet of tropical carnivores. Significance: Results from the present study have strong implications on feeding ecology of tropical felids. Present study refined previous understanding of biomass contribution of different prey species in large felid diet by substantially increasing roportion of medium prey consumption. Such inferences question niche separation of sympatric large felids on the basis of prey species of different sizes, where large carnivores like tiger optimizing on large prey like gaur (Bos gaurus) and sambar (Rusa unicolor). while medium felids like leopard maximizing on chital (Axis axis). Domestic livestock significantly reduced in carnivore diet, reducing livestock depredation rates. indicating lower human-carnivore conflict levels.