Theses and Dissertations
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Item Assessing Habitat Use and Activity Pattern of Hoolock Gibbons (Hoolock hoolock) in the Mosaic Landscape of Garo Hills(Wildlife Institute of India, Dehradun, 2025) Passah, Betwonsaoo; Lyngdoh, Salvador; Kumara, H.N.Primates react to environmental disruption in a variety of ways. Their home range and activity pattern are often linked with anthropogenic disturbance of the landscape. This study focuses on Hoolock Gibbons (Hoolock hoolock) in Garo Hills, Meghalaya, which is a highly arboreal primate and the only ape in India. Hoolock gibbon’s habitat in the Garo hills is being degraded due to the increase in the conversion of forest land into plantations. As most of these forests where the gibbons are located are managed by the community, these forests face overexploitation, which threatens the endangered Hoolock Gibbons habitat. This study aims to establish a baseline Hoolock Gibbon Ecology in the community-managed forest and protected area in the mosaic landscape of Garo Hills, Meghalaya, by examining their habitat use and activity pattern. The main objective is to determine the Gibbon's habitat use within its home range and examine their activity patterns in different forest types. The study is conducted in Daribokgre CR (a continuous forest patch adjoining Nokrek National Park), Dura Kalakgre CR (a small strip of CR which is surrounded by abandoned jhum and active jhum), and an Areca nut plantation which is located in Rensengre close to Selbalgre CR. In each area, one group is chosen and tracked for 20 days. Geo-coordinates and behavioural data were collected, with vegetation sampling and disturbances within a 1 ha cell size grid, which was overlaid on the location points. QGIS was used to map habitat use based on the geospatial data, and the Generalised Linear Model (GLM) was used to check the influencing factors. The activity budget was calculated to understand the behaviour patterns. Across the three studied groups, the habitat types were different group in Daribokgre (Forest group) is dominated by forest patches, the group in Dura Kalkgre (Jhum group) was dominated by abandoned jhum, and the group in Rensengre (Plantation group) was dominated by plantation, and their home range size were 24 hectares, 30 hectares, and 23 hectares, respectively. GLM reveals a significant effect only for the group in the disturbed habitat on the intensity of use. Overall, habitat use patterns and activity patterns varied across the groups, reflecting in behavioural and habitat preference.Item Molecular phylogeny and phylogeography of Himalayan langur species complex(Wildlife Institute of India, Dehradun, 2021) Arekar, Kunal; Sathyakumar, S.; Karanth, PraveenAccumulation of genetic variation within different populations of a species is shaped by temporal changes in geography, climate and population demographic history via a combined effect of genetic drift, gene flow and selection. Physical barriers such as rivers and mountain ranges are known to prevent gene flow among populations, and over time, create population genetic structures. Given this background, present study used an integrative taxonomy of the Himalayan langurs and I further studied the role of different river valleys in the Himalayas as a potential barrier to gene flow.Item Golden Langur Distribution, Habitat Selection and Corridor – Connectivity: Assessing Patterns and Addressing Threats(Wildlife Institute of India, Dehradun, 2024) Basumatary, Rishi; Nath, Anukul; Gopi, G.V.; Chetry, DilipThe Golden Langur (Trachypithecus geei), is an endangered colobine primate, confined to fragmented forest patches in western Assam, India, and south-central Bhutan. The golden langur has experienced severe habitat loss and fragmentation due to ethnolinguistic and religious conflicts between the late 1980s and late 1990s, followed by developmental activities in western Assam. The primary threat faced by the golden langur in India are the rapid reduction of its natural environment and the fragmentation of its habitat. Factors such as a limited population size, the breakdown of meta-population dynamics, and unique traits of a species often make a population in a fragment more likely to experience local extinction. Due to the significant decline in the range of Golden langur in both Bhutan and India, as well as the ongoing destruction of their habitat in India, it is imperative to safeguard even the smallest local populations. The populations residing in these fragmented Reserved Forests and Proposed Reserved Forests are effectively confined, separated from the primary breeding population, and susceptible to demographic and genetic influences. The objective of this study is to understand the current distribution, suitable habitat, and connectivity of corridors for the severely fragmented southern population of golden langur in India. Additionally, the study aims to examine the specific habitat preferences and demographic patterns of langur groups, as well as evaluate the threats that this fragmented population faces. The study was carried out in nine fragmented forest patches that includes Wildlife Sanctuary (WLS), Community managed RF (CMRF) Reserved Forest (RFs), and Private Rubber Plantations and Adjoining Forests (PRP_AF). In the present study, a total of 123 trails, ranging from 0.4 km to 1.6 km, were walked, covering a total distance of 118.72 kilometers. During these surveys, a total 51 troops (including 8 multi-male multi-female troops and 5 all-male groups), consisting of 499 individuals were encountered. The mean group size and age-sex ratio between different protected regimes that include wildlife sanctuary (WLS), community managed RF (CMRF), reserved forest (RF) and private rubber plantation and adjoining forests (PRP_AF) were compared. The overall mean group size of the langur was 9.78 (± 0.69 SE). Of the total 499 individuals, 13.22 % comprised of adult males, 41.88 % adult females, 16.83 % sub-adults, 10.02 % was juveniles and 18.03 % was infant. The average age-sex ratio of adult males to adult females was 0.287 (± 0.04 SE), juveniles to adult females was 0.224 (± 0.02 SE) and infants to adult females was 0.407 (± 0.04 SE). The infant to female ratio was found higher in wildlife sanctuary as compared to other reserved forests in the study area. The current study revealed that approximately 883 km² of the area is highly suitable for the endangered golden langur. Percent forest cover was found to be the most important variable in determining the probability of occurrence of golden langur in India. The corridor connectivity analysis showed high conductance for corridors namely Bamungaon and Khoragaon RF. Similarly, the connectivity is permeable between Kakoijana and Bamungaon. Other corridors identified in the study are Bhumeshwar Hill, Nakati RF and Kakoijana RF. On the other hand, there is high conductance among corridors of Chakrashila WLS and Nadangiri RF. Additionally, fine scale habitat selection study showed that tree species diversity, canopy cover and food plant density are the key in determining the occurrence of golden langur. In the last six years, a total of 56 mortality and injury incidents were reported from the study area which include 45 deaths and 11 injuries. Electrocution accounted for 29 cases, especially near forest edges, while 21 road accidents occurred mainly on national and state highways, as these roads are broader and have higher traffic volumes compared to village and town roads. Most accidents happened in the corridors between Chakrashila WLS-Nadangiri RF and Kakoijona RF-Bamungaon RF. Specific measures need to be taken to minimize electrocutions and road accidents of golden langur in the region. Mitigation measures like insulating electric lines and road safety protocols such artificial canopy bridges (ACB) and metal animal overpasses (MAOP) are essential for safe and easy movement along these corridors for the golden langur's survival in fragmented habitatsItem Beyond the forest: Intraspecific and interspecific aggression in Rhesus macaques (Macaca mulatta)(Wildlife Institute of India, Dehradun, 2024) Santosh, Charushree; Kumara, H.N.; Mahajan, PrashantRhesus macaques and human have been coexisting from a long time. Living in such close proximity to each other have bought various challenges to both species. Some challenges could be solved by behavioural modifications. This study looks at how various factors affect the aggression in both macaques and humans towards each other and their conspecifics. This study helps in understanding the frequency of aggression in macaques towards each other and humans in different settings. Direction of major aggressive interactions and the factors behind these events were also noted. Human aggression towards macaques were also seen. Most common reason for human initiated aggression was property damage while, for macaques it was threat. This kind of behavioural studies help us manage conflict with this communal species and also lets us see how human presence and behaviour might influence macaque behaviour.Item Intra-specific variation in seed dispersal effectiveness of Lion-tailed Macaques Macaca silenus(Wildlife Institute of India, Dehradun, 2024) Bindu, K.; Kumar, H.N. Dr. H. N. Kumara Dr. Navendu Page Dr. Rohit Naniwadekar; Page, Navendu V.; Naniwadekar, Rohit1. Tropical forests are one of the most biodiverse ecosystems on Earth. Seed dispersal is one of the important interactions that maintains species richness and ecosystem functions. Vertebrate frugivores, especially birds and mammals, play a crucial role in dispersing seeds. The dispersal effectiveness of these dispersers is influenced by factors such as size, age, sex, dominance hierarchy and behaviour types. Invasive species pose significant threats to tropical ecosystems, rapidly forming mutualistic relations with native dispersers. This study focuses on the lion-tailed macaques Macaca silenus in the Western Ghats to explore how age-sex categories influence seed dispersal of native and exotic species in terms of diversity and quantity of fruits consumed, quantity of seeds dispersed, daily distance travelled and seed deposition site. 2. I employed non-invasive behavioural sampling on four troops of the lion-tailed macaques for four months. Focal animal sampling of 375.9 hours was employed on individuals belonging to three age sex categories, including adult males, adult females and subadults. Faecal samples were collected to assess quantity of seeds dispersed, and the substrate at seed deposition site was recorded. The movement of focal individual was tracked for the entire duration of the observation. 3. Subadults consumed higher diversity of fruits than females and males. Subadults also consumed more native fruits, while females consumed more non-native fruits. The pairwise dietary overlap between all age-sex categories was high. The rate of consumption of nonnative fruits increased as day progressed. Subadults dispersed significantly less Ficus seeds than the other age-sex categories. Daily movements showed no significant differences across age-sex categories. However, I found weak evidence of males being more likely to disperse seeds on trees, which could be more suitable for Ficus germination. The differences in 7 feeding patterns also highlight the greater importance of subadults in the dispersal of a greater diversity of fruit plant species. 4. The invasives Coffea spp. and Lantana camara constituted up to 90% of the diet of the three age-sex categories. There was difference in the relative proportions of these two species. Males consumed more Coffea spp., whereas subadults and females consumed more Lantana fruits. The macaques dispersed Ficus seeds in clumps, increasing the risk of predation or microbial infection. 5. This study generates novel information on intra-specific variation in seed dispersal, a relatively understudied topic. It also highlights lion-tailed macaques' significant role in dispersing alien invasive species in degraded rainforests and provides valuable insights into their understudied role as seed dispersers.Item How Disturbed are the Disturbed Ones ? Impacts of Anthropogenic Stressors on the Socio-Ecological Interactions of Terai Gray Langur (Semnopithecus hector) in Shivalik Hills(Wildlife Institute of India, Dehradun, 2021) Dwivedi, Divya; Habib, Bilal; Qureshi, QamarAnimals respond to the changes in their habitats numerically and behaviourally. Alterations caused by anthropogenic stresses, like habitat degradation, fragmentation, urbanisation, changes in land use patterns, etc., changes the ecology of most species. Understanding the patterns adopted by these species to successfully survive and reproduce in such habitats is of utmost importance. This study tried to understand the impacts of human disturbance on the socio-ecology of Terai Gray langurs in Shivalik landscape, by comparing the ecology of langur troops inside the protected forest with the troops in disturbed forest. Four troops of Terai Gray langur, of comparable sizes, two in each treatment were selected.