M Sc Dissertation(WII)
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Item Seasonal Habitat use of and Resource Partitioning between Two Sympatric Crocodilian Populations (Gavialis gangeticus and Crocodylus palustris) in Katerniaghat Wildlife Sanctuary, I(Wildlife Institute of India, Dehradun, 2011) Choudhary, Shikha; Choudhury, B.C.; Gopi, G.V.Gharial (Gavialis gangeticus) and Mugger (Crocodylus palustris) are sympatric in their distribution range in some of the Northern River system of Indian sub-continent. Katerniaghat Wildlife sanctuary along Indo-Nepal border in Uttar Pradesh harbours the second largest breeding population of critically endangered Gharial, after National Chambal Sanctuary. Several studies have been carried out on the ecological aspects of Gharial and Mugger separately but very few studies exist on the sympatric populations and the mechanisms favouring the coexistence of the species. This study has tried to fill this gap by investigating how the resources are shared (Basking sites and Nesting sites) and what are the key requirements that lead to the selection of a particular basking and nesting site. Temporal separation across species and size classes and preference for nearest neighbor has been established. Relative abundance in terms of encounter rate across season, river segments and a gradient of disturbances were studied. Other aspects that have been looked into detail in this study are the impact of tourism and illegal fishing on the flight distance of Gharial and Mugger. Data were collected from December 2010 to May 2011, covering two seasons (late winter and early summer). Entire study was carried out using a non-mechanised boat. Habitat parameters for every sighted basking crocodile were recorded for habitat use and for determining the habitat availability variables at every 100 meters on both banks and on islands were recorded. Nests were located by following the spoor marks of crocodiles. Gharial and Mugger were divided into three size classes (SCI - 3m). Once in a month day survey was carried out to estimate the relative abundance and on every alternate Monday temperature and number of basking individual were recorded at every hour from 0600 to 1800 hrs from a watch tower. Flight distance of crocodiles was recorded from a non-mechanised boat and a mechanised boat by accompanying the tourists. Relative abundance as mean encounter rate (#/20km) was maximum for Gharial juveniles followed by Gharial adult. Mugger juvenile had lowest mean encounter rate (#/20km). Encounter rate was not uniform for the river and it varies across season also. Maximum sightings took place in river segments with sand bars irrespective of moderate to high disturbance. With increase in mean ambient temperature encounter rate declined. Basking sites were selected during summer by Gharial based on depth gradient, current land usage, island, distance to water, slope, platform height and soil moisture while selection of basking site by mugger was based on current land usage, distance to water and depth gradient. In winter, Gharial selected sites based on slope, platform height, soil moisture, current land usage, distance to water and place while Mugger looked for current land usage, distance to water, islands and banks. In winter, there was no temporal segregation between different size classes of Gharial and Mugger while in summer there was a temporal segregation between and within size classes 0f Gharial and Mugger. Choice of slope, height, soil moisture, places and substrata for basking sites were different for Gharial and Mugger. Gharial preferred very gentle slope while Mugger preferred a slight slope. Gharials do not prefer elevated basking platforms whereas Mugger was found basking on elevated platform. GhariaI preferred moist areas for basking and Mugger basked even on little dry substrate. Gharial was seen mostly on Islands and Muggers on banks. Among basking substrate Gharial preferred sand & sand+silt, whereas Mugger was found on a variety of substrata. Mugger moved to side streams (Nalla) in summer while Gharial kept on preferring island for basking. For nest sites there is a significant difference in the use of slope, height, distance to water, places and substrate by Gharial and Mugger. Flight distance for crocodiles was more when there was a disturbance from non-mechanised boat than from a mechanised boat. Mechanised boat is mainly used for tourism purpose while non-mechanised boat for illegal fishing by local people. Between species Mugger was more tolerant to human presence than Gharial. Among hatchlings and adults of Gharial, hatchling showed a late response to disturbance while adults used to be the first one to slide in to water. Girwa river of Katerniaghat Wildlife Sanctuary is one of the very few rivers of India where Gharials re breeding in wild. Though the river stretch is about 20 - 21 km only a small stretch of 5-8 km harbours the maximum number of Gharial and Mugger. This small section is used for both basking and nesting and it is very crucial to protect this small stretch in order to save a critically endangered species from the brink of extinction.Item Habitat and Food Resources Use in Relation to Sex Age and Group Size in Sambar (Rusa unicolor) During Winter in Dry Tropical Deciduous Habitat of Ranthambore Tiger Reserve, India(Wildlife Institute of India, Dehradun, 2011) Goswamy, Amit; Goyal, S.P.; Sankar, K.The study of habitat use depends on various factors' like environmental conditions, resource availability, physiological condition of an animal and sex. The present research for my dissertation shows that it does exist and it attempts to explain how it is happening. Sambar is a major prey species of tiger and other big cats across most of the parks in India. For the conservation of large predators it is important to evaluate and study the habitat requirement of its major prey species in detail to the level of its age and sex categories. My field study was undertaken between Dec 2010 to March 2011. Intensive study area of 90 sq km was selected in Ranthambhore. to quantify resource availability and use by different categories with respect to sex, age and group size during winter. It was found out that there is a difference in the habitat use of sambar due to sex, age and group size categories, out of the many parameters evaluated and comparisons made it was seen that though in some cases the differences were not profound, and some showed only minor changes, but in majority of the cases the trend observed was as per the expectation. Where smaller body size male animals < 3 yrs) and female associated with fawn and subadults always prefer areas having a good quality resource whereas the adult male and sambar in large group size were mainly in the areas of abundant resource rather than the quality.Item Factors Influencing Movement Pattern Habitat Use and Distribution of King Cobra (Ophiophagus hannah)- A Multiscale Approach(Wildlife Institute of India, Dehradun, 2011) Rao, Chetan S.; Talukdar, G.; Choudhury, B.C.The king cobra (Ophiophagus hannah) is the largest species of venomous snake in the world. It is a widely distributed species occurring in India and Southeast Asia. Most of the habitat use studies of ophidians are responses of ambient temperature. These results are often correlated with temperate areas where there is a significant shift in temperature annually. In tropical ecosystems, to understand ecology of a large bodied species like the king cobra would be interesting, knowing the fact that very little work has been done so far. The objective of my study was to procure relationship of ecographic variables on movement pattern, habitat use and distribution of king cobras at an individual and at a population level. This study was carried out in Agumbe, Karnataka in the Western Ghats region of India for 4 months during December 20 I 0 to April 2011 . Habitat utilization points were sampled throughout the study area, which basically was placed within the boundaries of a 2x2 sq.km grid enclosing all the presence locations collected during five years from the ongoing King Cobra Telemetry Project conducted by the Agumbe Rainforest Research Station and the University of Arizona in collaboration with the Karnataka state forest department. Retreat sites (n=262) were selected where the tagged (n=5) had been recorded and sampled for microhabitat variables. Nest sites (n=13) were also looked into, to explore site selection by females. A total of 30 ad libitum sightings of king cobras were recorded during the study. Prey density walk was carried out to derive a relative abundance based on encounter rate in the study area that came to be 1.24 animals/km. A total of 9 species of prey were encountered during prey density walks. The kernel estimates and minimum convex polygon for four radio tagged individuals was calculated for home ranges and area vs. availability was computed for habitat preference and use using Jacob's (1974) Index. The results of this study show a strong correlation of ambient temperature of range 20- 35°C (Beta coefficients 7.7eI0-l ± 0.0545) and relative humidity (70-90%) (Beta 15 coefficients 1.25 ± 1.14) with movement pattern and habitat site selection and also affect distribution patterns of this particular king cobra sub population. It is also found that king cobras do not particularly obligate themselves to a particular habitat type except for some degree of preference towards evergreen forest. The microhabitat however, influencing king cobra movement and habitat use are fallen logs on the forest floor (Beta coefficients 2.327e+00 ± 5.113e-Ol) and dead vegetation on the forest floor (Beta coefficients 2.042e-02 ± 6.796e-03) which have a stronger correlation with presence while ground burrows show a negative correlation. Leaf Litter Depth in the forest floor in sites with range of 4-7 inches deep (Beta coefficients 0.64269 ± 0.30998) influences nest site selection. Using secondary rescue data of five years and all the other presence records for king cobras in the wild, I ran a MaxEnt presence only model (auto model) using only environmental variables taken from BIOCLIM to test environmental parameters influencing distribution. The places of higher precipitation within the study area indicate a higher influence on occurrence and places of higher temperature and aridity regimes does not indicate occurrence of king cobras. The management recommendations for conserving such large bodied snakes would be a multidimensional approach. The local people within the study area do not kill king cobras, due to religious reasons. However, these attitudes are changing and so also some of the tolerant ideologies of the local people. King cobras have been found to occur more in a landscape matrix dominated by evergreen forests and decline in evergreen forest due to land use conversion could be the emerging possible threats to king cobra in the Western Ghats.Item Species Assemblage and Differential Basking Habitat Use of Freshwater Turtles in a Gradient of Mahanadi Riverine Ecosystem, Orissa(Wildlife Institute of India, Dehradun, 2009) Jani, Chandan; Choudhury, B.C.; Sivakumar, K.Of the seven species of turtles recorded in the Mahanadi River, this study recorded five species of freshwater turtles between Satkosia Gorge Wildlife Sanctuary and Khakadi (Near Cuttack city) during November 2008 to April 2009. Of these five species, four were softshell turtles (Nilssonia gangeticus, Nilssonia hurum, Chura indica, Lissemys punctata) and one was hardshell (Pangshura tentoria). Relative abundance in terms of mean number of individuals sighted per kilometre was estimated. The results showed that Pangshura tentoria was most abundant and was recorded over all the sampling zones, followed by Nilssonia gangetic vs Nilssonia hurum and Chitra indica. The latter three were not distributed as commonly as the former. Lissemys punctata was not included in the report as the species never sighted during the sampling secession. However, the species was found to get captured in incidental fish catch during the study period. The low abundance of Chitra indica and Nilssonia hurum might be due to degradation of their habitats. These two species are known to refer undisturbed and wider river stretches which are diminishing in the Mahanadi River. The habitats of the river stretch between Satkosia Gorge Wildlife Sanctuary and Kakhadi varied significantly and thus, explaining the variation in the species richness as well as abundance. The major habitat variables, which have highly influenced the turtle abundance were river flow, river width and river bank characteristics. Highest abundance of species was found in the non-riparian flow zones and river stretches with rocky and sandy banks, where the habitat heterogeneity was greater. These two sampling zones also experienced the least anthropogenic pressures. Choice in habitat use for basking in turtles was also observed. The choice of the habitat varied between species. Nilssonia gangetic and Nilssonia hurum preferred areas which had greater river bank width with shallow water near the bank. Chitra indica preferred areas where both river depth and river width were higher whereas bank slope, river slope, ground cover, alternative basking substrate and immediate water depth was lower. Pangshura tentoria preferred areas with greater river and bank slope along with greater availability of alternative basking substrate and greater immediate water depth. On the other hand they also preferred the habitat more close to the river with lower bank width and moderate river depth and moderate river width. Major threats to turtles in the Mahanadi river (sampling zones) are due to anthropogenic pressure and habitat degradation. Some of the threats were found to be consistent over the sampling zones. The study shows that Pangshura tentoria was highly tolerant to all prevailing threats in the Mahanadi river but, Nilssonia hurum and Chitra indica were adversely affected by these threats all along the river. This study found that there was a negative correlation between the turtle abundance and presence of threats such as sand mining, pump house, fishing and pollution. Sand mining adversely affected the basking habitat of most of the turtle species. Pump houses were largely avoided by the turtles which may be due to the vibrations or noise created at these stations. Unintentional by-catch of turtles during fishing was also observed especially in the braided flow zones and inundated static flow zones of the Mahanadi river. Sand mining and fishing are identified as the major threats to the turtles in the Mahanadi river, which should be monitored and regulated. Sand mining should not be allowed during the breeding season of the turtles especially in the area of Non riperian flow zone and braided flow zone. These two sampling zones were identified as the Important Turtles Areas (ITAs) in the Mahanadi River. Alternate livelihood options should be identified and implemented in order to reduce people's dependency on fishing in this region. Nature education and awareness programme clearly addressing the reason for declining of turtles and their habitat in the Mahanadi river needs to be launched.Item Habitat use and food selection by wild and domestic ungulates in the Sikkim Transhimalaya.(Wildlife Institute of India, Dehradun, 2007) Chanchani, Pranav; Rawat, G.S.By defining a resource, determining the resources available to animals and sampling the array of resources actually used by an animal (Krebs 1999), it becomes possible to gauge the nature of interactions between species. This study explored aspects of resource use by diverse assemblage of wild and domestic herbivores including The Tibetan argali (Ovis ammon hodgsoni), Tibetan Gazelle (Procapra picticaudata), kiang (Equus kiang), blue sheep (Pseudois nayaur), domestic yak and sheep in a Trans-Himalayan environment during the lean winter period. Sampling was carried out in a systematic manner using trails, as well as by sampling opportunistically. To quantify vegetation, a 3.52 Ian grid was overlaid on an image of the study area, and grids were randomly picked from these for random sampling. A number of habitat and vegetation variables were measured or noted for all ungulate sightings or within vegetation sampling stations and these were used in analysis to ascertain patterns of habitat use and food selection. U sing a hierarchy of spatial scales, the study modeled animal distributions, and investigated the use of habitats and food habits of ungulates in relation to the availability of these resources in their environment. The study's major findings were that all ungulates were found to occur in the true Trans-Himalaya except for the blue sheep which selected more mountainous terrain in the transition zone between the greater and Trans-Himalaya .. Statistical tests of significance revealed that ungulates differed from one another or from random in their use of resources. Further, terrain features appeared to influence habitat selection to a greater-extent than vegetation. Finally, the findings of this research indicate that although the wild and domestic ungulates of this region all exist in relatively large numbers, they tend to vary in their use of habitats and food either by differences in their distribution, or in the selection of finer environmental (habitat and food) variables. The study therefore concludes that competitive inter-specific interactions are not very apparent in this region.Item Habitat use by Chital (Cervus axis) in Dhaulkhand, Rajaji National Park, India(Wildlife Institute of India, Dehradun, 1993) Bhat, Sridhar D.; Rawat, G.S.A study on the habitat use by chital or spotted deer (Cervus axis) was conducted in Dhaulkhand Rajaji National Park, from November 1992 to May 1993. The objectives of the study were to understand the spatio-temporal use of habitats by chital and to identify the factors that govern the patterns of habitat use. Foot transects were used to estimate the densities of chital and quantify the availability and utilization of resources.Item Habitat Use, Group Size and Activity Pattern of Goral (Nemorhaedus goral) in Simbalbara Sanctury (Himachal Pradesh) and Darpur Reserved Forest (Haryana) India(Wildlife Institute of India, Dehradun, 1993) Pendharkar, Anand; Goyal, S.P.A study on the habitat use, group size and activity patterns of goral (Nemorhaedus goral) was undertaken from November 1922 to May 1993 in Simbalbara Sanctuary (Himachal Pradesh) and Darpur Reserved Forest (Haryana). Data on availability of habitat types, vegetation types, slope, aspect and cover and their corresponding use (N=230 sightings), were collected along six search paths. Group size and activity pattern data were collected by walking along search paths and using instantaneous scan sampling. The broad habitat types identified were: Valley slope, Grassy slope, Ridge top flat, Nala slope, Valley bottom flat, Ridge top slope and Valley ridge slope. The vegetation types identified in the study area were: Sal forest (SF), mixed forest (MF), mixed forest grassy slope (MFGS), mixed forest riverine (MFR), sal forest riverine (SFR), pine-mixed woodland (PMW) and mixed forests with khai plantation (MFKP).The characteristic features of habitat and vegetation types and seasonal variations in them are discussed.The major findings of availability-utilization analysis were : Goral shewed preferential use of grassy slopes in summer. Valley bottom flat was used less in both the seasons. Mixed Forest was preferred in both seasons, whereas Mixed Forest Grassy Slopes were preferred only in summer. Sal Forest, Sal Forest Riverine and Mixed Forest with Khair Plantations were used less in both the seasons. A preferential use of the steep slopes was observed in winter. In summer there seemed to be no selection for terrain type. South facing slopes were preferred in both the seasons. Extremely low shrub cover and medium grass cover were selectively used by goral. Major features of goral group size and activity pattern were: Goral was predominantly a solitary species forming loose aggregations of upto eleven individuals. Average group size of goral did not vary significantly (N=230, d. f.=3, p=0.05, X" - 0.98) between seasons, but during late evening hours, comparatively larger groups were observed in winter (N=127, d.f.=4, p=<0.02, X2 - 12.42). Group sizes were comparatively larger in disturbed areas (N=230, d. f.=3, i i i p<0.01, = 12.75). A significant difference in proportion of time spent in different activities was observed (N=416, c/.f. = 8, p<0.001, X2 = 37.59), between winter and summer. Nevertheless, activities and proportions of active and inactive individuals varied significantly over different hours of the day (N=192, d.f.=2, p<0.01 , 10.43).Item Habitat Use by Goral (Nemorhaedus goral bedfordi) in Majhatal Harsang Wildlife Sanctuary Himachal Pradesh, India(Wildlife Institute of India, Dehradun, 1993) Mishra, Charudutt; Johnsingh, A.J.T.Studied the habitat use pattern of goral (Nemorhaedus goral bedfordi} in Majhatal Harsang Wildlife Sanctuary in the Himalaya to determine its habitat requirements. Of special interest were the roles of forage availability and quality and the antipredator strategy of goral in determining its habitat selection. These factors are of paramount importance in influencing the habitat selection by mountain ungulates. Diet composition of goral in terms of the proportions of graminoids versus browse was determined through pellet analysis. Its escape strategy was determined by direct observation. These results were then related to the actual habitat use patterns, which were determined by obtaining and quantifying locations of goral (n=334) over two seasons, along five monitoring trails. Use of each habitat category was interpreted with respect to its availability. A non-mapping technique was used for determining the availability of each habitat component. I identified nine vegetation types based on physiognomy and floristics. These were: Open Pine Community (OPC), Dense Pine Forest (DPF), Open Oak-Pine Community (OOPC), Dense Oak-Pine Forest (DOPF), Nullah Oak Forest with Low undergrowth (NOFL), Nullah Oak Forest with High undergrowth (NOFH), Euphorbia-Woodfordia-Dodoenia Scrub (EWDS), Open Euphorbia Scrub (OES) and Low Altitude Nullah Forest (LANF). Both forage quality and the antipredator strategy had a profound influence on habitat selection by goral. Goral was a grazer. It was partial to the younger, more nutritive grass phenophases - a prediction that can be made on the basis of its small body size. It preferred open areas with extensive grass cover. Forest cover, along with cliffs, was an important escape area for goral. But it avoided areas with extensive shrub cover. Such areas have little grass. Besides, the shrub cover obstructs visibility and quick movement, and makes the animal vulnerable to predation.Item Aspects of Foraging, Activity, Habitat Use and Demography of Rhinoceros (Rhinoceros unicornis Linn.) in Royal Chitwan National Park, Nepal(Wildlife Institute of India, Dehradun, 2003) Kandel, Ram Chandra; Jhala, Y.V.The study was conducted between November 2002 to June 2003 in the Royal Chitwan National Park, in Central Terai which arbors the largest population of the Great One-honed Rhinoceros (Rhinoceros unicornis Linn) in Nepal. I studied time Activity budget, Habitat use, preference, food habits and ranging pattern of free ranging rhinos by continuously monitoring them from elephant back for 130.5 hrs (10 sessions of 7-24 hr each)Item Habitat use by the Great Indian Rhinoceros (Rhinoceros unicornis) and the other sympatric large herbivores in Kaziranga National Park(Wildlife Institute of India, Dehradun, 2001) Banerjee, Gitanjali; Rawat, G.S.; Choudhury, B.C.A study on the habitat use by the Great One horned rhinoceros (Rhinoceros unicornis) and three other sympatric ungulates was carried out in Kaziranga National Park (KNP), Assam during December 2000 to April 2001. KNP supports more than half the world's population of the Indian Rhinoceros, a highly endangered species. Since this park also supports a high diversity and density of herbivores coexisting in a typical floodplain habitat, it was an ideal place to conduct the following study. The study aimed to determine how 4 large herbivore species rhino, wild buffalo, swamp deer and hog deer achieve spatial and temporal separation across two seasons. The study also investigated how nutritive content of the forage determines habitat selection by these species. KNP was an ideal place to study habitat use patterns by these four sympatric species due to the seasonal variation of forage quality caused by the practice of annual burning. Sampling for animal abundance within each habitat type over two seasons was done by monitoring transects. Feeding observations were obtained by scan sampling. Laboratory analysis was done to determine the nutritive content of the available forage during winter and summer. Seasonal and spatial differences observed in habitat occupancy patterns by the ungulate species within KNP seem to be a way of partitioning resources in order to minimize competition. During the winter season all ungulates selected the short grasslands for feeding. The wild buffalo and the swamp deer showed no variation in the habitat occupancy patterns showing a positive selection for the short grasslands. However, rhinos and hog deer were observed to prefer the tall, burnt and sprouting grasslands in summer for feeding during summer. When habitat occupancy patterns were correlated with the nutritive value of the forage it was found that all ungulates tracked high crude protein levels in available forage. Rhinos and hog deer formed an association that exploited areas that have high crude protein and low silica content. Wild buffaloes and swamp deer show less flexibility in habitat occupancy patterns and were observed to feed in short grasslands where there was a relatively high amount of crude protein available during both the seasons. The study revealed that crude protein played an important role in determining habitat use by hog deer, which shows a linear relationship with crude protein. Forage volume, an indicator of available food played a significant role in determining habitat use patterns for the large bodied ungulates, namely the rhino and the wild buffalo which is in keeping with their physiology and body requirements. There seems to be partitioning of space by the ungulates on the basis of body size and dietary separation. Rhino and hog deer were observed to formed one guild whereas wild buffalo and swamp deer formed another one. These two groups differed in the pattern of habitat occupancy suggesting that ecological separation in Kaziranga National Park, perhaps occurs on the basis of differential use of the habitat by ungulates that have a similar body size. There was an observed complementation of body sizes within each association. A large bodied ungulate associated with another ungulate that was much smaller in size. and therefore, had different ecological needs.