M Sc Dissertation(WII)
Permanent URI for this collectionhttp://192.168.202.180:4000/handle/123456789/3
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Item Investigating the Social Structure of Female Asiatic Lions(Wildlife Institute of India, Dehradun, 2019) Borah, Doli; Kolipakam, Vishnupriya; Jhala, Y.V.In this study the social structure of lion prides in the Gir landscape through behavioural observation discussed. the study was carried out in and around Gir protected area of Gujarat. In India the Gir forest only has the last free ranging population of Asiatic lion.Item Dogs Finally have their Day? Aspects Changthang Wildlife Sanctuary Ladakh(Wildlife Institute of India, Dehradun, 2019) Subhashini, K.; Kawlni, Lallianpuii; Jhala, Y.V.In a country with increasing numbers of free-ranging dogs that often times foray into wildlife habitats, even their presence has been established as a threat for biodiversity conservation in any landscape. Stated that they pose a problem, the means and extent of the problem needs an understanding of their ecology. This study aims to understand the effect of anthropogenic subsidies on the population, ranging, and subsidy resource usage patterns of free-ranging dogs. Placing subsidies in the centre of the ecology of these dogs, the study also attempts to understand inter-species interactions and potential for dogs to act as disease reservoirs in the unique trans-Himalayan landscape.Item Has conservation gone to the dogs? : ecological aspects of free ranging dogs of the Thar(Wildlife Institute of India, Dehradun, 2017) Mohandas, Monisha S.; Jhala, Y.V.; Qureshi, Qamar; Dutta, SutirthaOne of the few mammals to have a near-global distribution, dogs (Canis familiaris) are an introduced mammalian predator. Dogs have contributed to 11 vertebrate extinctions and are a potential threat to 188 threatened species globally. This study investigates population sizes, ranging patterns, behavioural activity, and resource utilisation of free-ranging dogs in Thar landscape, Rajasthan. 2. Using double sampling framework, I calibrated effort-standardized counts (C) with mark-recapture based abundances (𝑁̂) that was used to estimate dog abundances within human habitation. Landscape-scale dog abundance was estimated using vehicle transect based distance sampling. Home ranges of nine free-ranging dogs was determined using locations from radio-telemetry. Resource use was quantified as feeding durations on various food items based on continuous monitoring. Resource availability was quantified as wild prey and livestock carcass density using line transect based distance sampling. This study provides information on important aspects of free-ranging dog ecology and their impacts in Thar landscape. It provides the basis required for implementing dog control programs in the landscape focusing on the flagship and critically endangered great Indian Bustard Ardeotis nigriceps.Item Assessment of grassland communities its use by mammals and mapping the potential habitat of Rhinoceros unicornis in Valmiki Tiger Reserve, Bihar(Wildlife Institute of India, Dehradun, 2017) Murari, Krishna; Talukdar, Gautam; Pandav, Bivash; Jhala, Y.V.This study was conducted to identify grassland vegetation communities associated mammals and to find out the potential habitat of Rhinoceros unicornis in VTR.Item Factors Governing the Spatial Distribution and Density of Asiatic Lions (Panthera leo persica) in Gir Protected Area(Wildlife Institute of India, Dehradun, 2015) Gogoi, Keshab; Jhala, Y.V.; Qureshi, QamarThis study is based on population estimation and spatial distribution of Asiatic lion.Item Computing Biomass Consumption from Prey Occurrences in Scats of Tropical Felids(Wildlife Institute of India, Dehradun, 2013) Chakrabarti, Stotra; Jhala, Y.V.; Qureshi, QamarA 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.Item Estimating the Status and Impact of Hunting on Tiger Prey in Bardia National Park, Nepal(Wildlife Institute of India, Dehradun, 2009) Malla, Sabita; Jhala, Y.V.; Qureshi, QamarA study was undertaken to understand the status of tiger prey species in relation to the hunting pressure in Bardia from November 2008 to April 2009. The prey densities were estimated using distance samplingItem Evaluating the importance of scale in estimating tiger populations(Wildlife Institute of India, Dehradun, 2007) Contractor, Deep; Jhala, Y.V.; Qureshi, QamarPopulation estimation is one of the most important aspects of ecological studies as it plays a pivotal role in establishing priorities for species specific conservation and for delineating management practices. The tiger serves as a flagship and umbrella species for conservation efforts in the Indian subcontinent but, unfortunately wild tiger populations are on a drastic decline owing to factors like poaching, habitat fragmentation and degradation. In such a scenario reliable population estimates prove to be of vital importance. Camera trapping technique has been widely used for population estimation of cryptic carnivores including tigers. An attempt was made, through this study, to arrive at population and density estimates for Corbett NP through camera trapping technique following the mark recapture framework and answering some key questions regarding the importance of sampling effort required for arriving at such reliable estimates. A total of 7865 trap nights yielded 358 captures of 103 individual tigers within an intensively sampled area of (MCP) 420.86 km2. The estimated density of tiger was 16.01 (±1.6) per 100 km2 for RPSV, a new approach to calculate effectively sampled area. These estimates coincided with the estimates using full MMDM method. Also, the conventional method of using half MMDM seems to overestimate the density. The estimated sampling effort required for arriving at accurate and precise estimates of the true population in terms of sampling occasions amounted to 35 - 40 days. Evaluation of the influence of trap density revealed that high trap density (25 traps/km2 ca.) is required to get reliable estimates of population irrespective of the underlying population/density gradient.Item Resource utilization and parental investment in the Indian for (Vulpes bengalensis) in Kutch, Gujarat(Wildlife Institute of India, Dehradun, 2005) Home, Chandrima; Jhala, Y.V.I studied the resource utilization patterns in the Indian fox (Vulpes bengalensis) with respect to diet in Kutch, Gujarat. Resource use and availability by foxes were compared between two habitats and between two seasons. Resource availability was quantified through transects laid in both the habitats for the different prey items: mainly mammals, birds, reptiles, arthropods and fruits. Resource availability differed in both the habitats as well as across seasons (summer and winter). Density of fruiting shrubs (particularly Zizyphus) and gerbil burrows were significantly different between the two habitats. Gerbil population mean obtained from different colonies trapped during the study period showed a significant relationship with the total number of burrows in the colony (R2 =0.969). Scats collected from den sites were used to quantify resource use of the Indian fox. The minimum number of scats that can be used to estimate the annual food habits of the Indian fox in' a dry arid area like Kutch is about 110 scats. Frequency of occurrence of prey species also differed across habitat and seasons. The food habits of the Indian fox comprised of varied items, mainly arthropods like beetles, orthopterans, scorpions and termites. Among the other items, rodents, hares, spiny tailed lizards, birds and eggshells as well as fruits have been found. Arthropods were the most frequently occurring prey items (75% and above), among them particularly the termites. They are seen to be selected more than availability within the habitat. This was indicated by the three methods used to compare use versus availability (Ivlev's Index, Bonferroni's CI, and Compositional Analysis). However the Indian fox is seen to maximize energy requirements by selecting gerbils next in the preference after arthropods being selected more than availability during most cases within the habitat. Density of breeding units evaluated in the scrubland showed a density of 0.1 O/sq Ian. The density of breeding pairs obtained in this particular study was much higher as compared to the ones reported earlier for Kutch (0.04-0.06/sq Ian) due to good rainfall in the preceding two years thereby indicating a good prey base as compared to other years.Item Evaluating Tiger (Panthera tigris) Population Estimation Approches in a High Density Area in Kanha Tiger Reserve(Wildlife Institute of India, Dehradun, 2005) Sharma, Rishi Kumar; Jhala, Y.V.Reliable estimates of status and population trends are critical for the conservation of large terrestrial carnivores as they play an important role in evaluating effectiveness of conservation efforts and also provide benchmark data for future management decisions. Camera trapping technique have been widely used for population estimation of cryptic carnivores including tigers, but the issues regarding sampling design and effort required to effectively sample an area have been paid less attention. An attempt was made to deal with these issues in the present study. The use of intensive search effort for tiger density estimation was also evaluated. Over a 30- day survey period, 33 camera trap sites were sampled in Kanha meadows of the Kanha Tiger Reserve. A total sampling effort of 330 trap nights yielded 39 photocaptures of 12 individual tigers over 10 sampling occasions that effectively covered a 111-km2 area. The model M(o) fitted the capture history data well. The estimated capture probability/sample, p-hat = 0.22, resulted in an estimated population size and standard error (N(SE TV)) of 13 (1.19), and a density (D(SE Z))) of 11.71 (1.74)7100 km2. Camera spacing was found to considerably influence the population estimation. An increase in camera spacing from 1.5 to 2.5 km resulted in a loss of 35% (n=7) of photo captures which consequently decreased the precision of the estimates, though accuracy was not affected. A reduction in the trapping effort in terms of reduced trap nights resulted in lower level of precision though the accuracy of estimates was not affected. Increase in the camera spacing from 1 to 2 km with a decrease in the number of sampling occasions (six) resulted in the loss of 42% of photo captures (n=12) and loss of 25% of individual tigers (Mz+/=9) thus underestimating the true tiger population by 16% ((N(SE N)) being 10(1.84) The data also suggests that the photo-captures are not likely to generate abundance index for species other than tigers, since the cameras are placed to maximize tiger captures in space and time. My results suggest that a thorough reconnaissance survey is of utmost importance for camera trapping studies as it can help to maximize the capture probability of tigers and circumvent the sampling problems. The different statistical estimator’s viz. capture-recapture, jackknife and bootstrap did not show significant differences in the population estimation. Bootstrap estimator performed better than jackknife in terms of greater precision. The differences between the density estimates generated by “camera trapping” (D=l 1.71/100 km2, S.E.=1.74) and “intensive search effort” (0=12.74/100 km2, S.E.=2.27) for tigers were not significantly different. Our results suggest that “intensive search effort” for tigers if used within capture-recapture framework can be used to arrive at reliable population estimation