M Sc Dissertation(WII)

Permanent URI for this collectionhttp://192.168.202.180:4000/handle/123456789/3

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Author: search.filters.author.Kumar, R.S.Subject: search.filters.subject.Uttarakhand

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    Nest site selection in Pallas’s Fish-eagle and nesting behaviour in the Rajaji-Corbett landscape
    (Wildlife Institute of India, Dehradun, 2024) Tangaria, Abhishek; Jha, Ashish; Pandav, Bivash; Kumar, R.S.
    This study investigates the nest site selection and nesting behavior of Pallas's Fish-eagle (PFE) across the sub-Himalayan tract in India, addressing a significant knowledge gap in the species' natural history. PFE, classified as Endangered globally and of high conservation concern nationally, exhibits unique nesting preferences and ecological requirements. Prior research, including studies from Bhutan and Bangladesh, has highlighted the species' preference for unobstructed nest trees and proximity to water sources and human settlements. However, comprehensive data from India remains limited. The study aims to explore factors influencing PFE's nest site selection, such as habitat quality, microclimate, food availability, and protection from predators and human disturbance. Additionally, it seeks to document the species' reproductive behavior, including hatchling development, parental duties, and nest predation pressures. Surveys covered segments of the Ganga, Kohlu, Kho, Palain, Mandal, Asan Barrage, Dakpatthar Barrage, and Ramganga, recording data on sightings and nest characteristics. A total of twelve nests were found, with only one destroyed by a storm. The majority of nests were built on Bombax ceiba and Shorea robusta trees, with an average height of 29.9m and GBH of 473cm. Behavioral observations were conducted at three accessible nests, monitoring parental presence, predator interactions, and nest guarding behavior. Spatial analysis in ArcGIS Pro considered various land cover types and environmental factors, finding that barren land and rangeland significantly influenced nest site selection. Euclidean distances to different land cover types and elevation were also key factors. Statistical analyses using R revealed correlations between tree height and nest height, and generalized linear models highlighted the impact of land cover and environmental variables on nest presence. Nest trees were typically tall and robust, with Bombax ceiba and Shorea robusta being the most commonly used species. These trees provided unobstructed branches and greater accessibility. The study also highlighted the importance of open land around the nest tree, aiding in vigilance and territory defense. At a macro scale, the presence of barren land and flooded regions positively influenced nest site selection, while slope and distance from rangeland showed negative correlations. Behavioral observations at three nests revealed high predation pressure, particularly from crows, and kites. The presence of human settlements increased predation incidents, affecting parental investment in nest defense.
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    Species interactions with in mixed species bird flocks along an Elevational gradient in the Western Himalaya.
    (Wildlife Institute of India, Dehradun, 2021) Gokhale, Pranav; Kumar, R.S.; Mohan, D.
    Mixed-species bird flocks (hereafter, “flocks”) are an interactive community of largely insectivorous birds, which move and forage together to gain enhanced access to resources and protection from predation. In this study, I aimed to investigate a question: do interspecific interactions within mixed-species flocks change along an elevational gradient? To test this, I carried out this study in the Garhwal region of the Western Himalaya in Dehradun District, Uttarakhand from January to April 2021 (spanned across two seasons). The study areas comprised of three field sites along an elevation gradient from western part of the Rajaji Tiger Reserve (300 m ASL) to Mussoorie (2200 m ASL). I sampled flocks and relative abundances of birds on the two pre-existing trails in each of the three field sites. I walked each trail 10 to 13 times. I recorded species identity, group/cluster size of all birds seen inside as well as outside flocks on the trail and within 10 m on either side of the trail. I assessed arthropod prey availability in winter for the flocking species by using branch bagging technique on the same trails. In total, I clipped 150 branches for the three elevations. I calculated species-specific flocking propensity for each elevation from the information on birds seen within and outside flocks. I used network density (potentially realised associations) and weighted degree (associated strength) to quantify the interspecific interactions (associations) within flocks. To control for the influence of species availability on flock network properties, I generated null flocks using an abundance-based null model. I recorded 80 flocking species in 412 flocks, of which, 179 flocks were observed at the High elevation, 156 at the Mid elevation and 77 at the Low elevation. Majority of species in the Western Himalayan flocks were insectivorous gleaner. I found insect prey availability (resource) to decrease with increasing elevation in winter. As expected, flocking propensity, network density and weighted degree increased with elevation in both seasons indicating greater potentially realised associations and high strength of associations between species. Interestingly, the Low elevation flocks disintegrated completely at the onset of summer possibly due to the greater availability of resources, or an upward migration of species for breeding. I did not analyse the Low elevation flocks in summer due to small sample size (n=5). Flocking propensity and network density decreased from winter to summer at Mid and High elevation while, weighted degrees decreased only for the Mid elevation. This is likely that true summer may not have started at the High elevation during the course of my fieldwork. To conclude, with increasing elevation in both seasons, species not just flocked more, but associated with many species and these associations became stronger, potentially due to the scarcity of resources. It is possible that species may not be able to access resources efficiently when foraging on their own at the High elevation, compelling them to participate in flocks to avail complementary benefits from many other species.
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    Niche partitioning between assamese and rhesus macaque in the Askot landscape of Uttarakhand, Northern India
    (Wildlife Institute of India, Dehradun, 2017) Justa, Priyanka; Kumar, R.S.; Talukdar, Gautam
    Closely related species often have similar requirements and these species need to have certain ecological adaptations to live in sympatry. Two congeneric species the Assamese (Macaca assamensis) and the rhesus macaque (Macaca mulatta) co-occurring in the Askot landscape of Uttarakhand were studied to understand the mechanisms allowing their coexistence. 2. Ecological niche differentiation for the two species was investigated by examining three possible modes of separation: activity pattern, diet and spatial use following observational protocols over a period of five months (December 2016-April 2017). Crop-raiding by macaques often results in human-macaque conflict. With the help of semi-structured interviews, attempts were made to access the level of conflict and people’s perception of these two macaque species. 3. Limited niche overlap was found between two primate species across the study duration. The Assamese macaque differed from the rhesus macaque in time spent on various activities. The former spent more time feeding and the latter in resting. Although 44% of all food items were consumed by both the species, only three of the ten major food items were shared. Assamese macaques preferred leaves and had broader niche breadth compared to rhesus macaques who fed more selectively on fruits. There was a significant difference in feeding heights, habitat and roosting site preferences of the two species. Differences in diet choice and roosting sites, in turn, resulted in differences in daily movement and home range of these species. Despite a partial home range overlap, both these species were found to be spatially segregated at a local scale. 4. The extent of niche overlap across winter and spring seasons in the area showed the greatest divergence in the diets of the two species in winter, while diet overlap was more pronounced in spring. As resources were abundant in the spring, an increase in niche overlap may not have lead to competitive interactions. Synthesis and application: Knowledge about differential resource use of macaques might help in assigning conservation priorities to the different species and their specific ecological niches along with designing species-specific management strategies. The study was able to distinguish the macaque's tendency to co-exist with humans.