M Sc Dissertation(WII)
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Item Investigating the roles of fire and cattle grazing on vegetation, invasives, and their implications on Bengal Florican (Houbaropsis bengalensis) breeding habitat use(Wildlife Institute of India, Dehradun, 2025) Thammaiah, Aadya; Nath, Anukul; Dutta, SutirthaGrasslands, though ecologically important, are often overlooked in conservation. These ecosystems are shaped by land-use practices such as fire and grazing, which can help maintain open habitats when appropriately applied. Mismanagement, however, can promote invasive species, threatening native biodiversity. The Bengal Florican (Houbaropsis bengalensis), a critically endangered grassland specialist, highlights the need for targeted conservation in such systems. This study assessed the combined effects of fire and grazing on grassland plant communities, including invasive plants, and Bengal Florican breeding habitat selection in Manas National Park. 2. For the vegetation survey, I selected study sites along gradients of fire frequency (based on 23 years of FIRMS data) and grazing intensity (using distance from human settlements as a proxy). At each site, I used circular plots to sample vegetation and assess species composition. To examine drivers of plant and invasive species abundance, I applied linear models (LMs), incorporating key covariates such as distance to forests, roads, and climate moisture index (CMI). I then used Indicator Species Analysis (ISA) to identify species associated with different fire-grazing regimes. I also performed a Linear Discriminant Analysis (LDA) to assess how well vegetation communities and structure could distinguish between different fire conditions. For Bengal Florican habitat assessment, I quantified vegetation structure visually and insect abundance using sweep netting in display and paired control sites. I used Binomial Generalised 8 Linear Models (GLMs) and Conditional Logistic Regression modelling to evaluate habitat selection by the species. 3. Tree and sapling densities peaked under intermediate fire, whereas shrubs and herbs had the highest density in low fire regimes. Saplings, shrub as well as grass cover peaked in low grazing regimes, but herb cover was highest in low grazing conditions. Among invasives, Leea asiatica and Chromolaena odorata were more frequent in intermediate fire, while Mikania micrantha and Ageratum conyzoides thrived under low fire. Grazing showed significant effects only on Mikania micrantha. ISA identified native species such as Dillenia pentagyna as indicators of low grazing and Cymbopogon flexuosus for medium and high fire regimes, among others. Bengal Florican selected sites with higher insect abundance, shorter vegetation (25–50 cm), with low (outside the PA) and high fire frequency (within the PA). 4. My results showed that plant communities showed species-specific responses to fire and grazing conditions. Bengal Florican habitat-use reflected a preference for open, short grasslands with high insect abundance. In conclusion, my study found that effective conservation requires tailored fire and grazing strategies that sustain open structure and control invasives, especially for the conservation of species such as the Bengal Florican.Item Assessing the Efficacy of Select Physical Barriers in Mitigating Human-Elephant Conflict in the Human-Elephant Shared Landscape of Golaghat District, Assam(Wildlife Institute of India, Dehradun, 2021) Das, Gitima; Gopi, G.V.Human-Elephant Conflict (hereafter “HEC”) is one of the most challenging issues both for elephant conservation and people’s wellbeing in the elephant landscapes. Management of which becomes extremely difficult without the implementation of appropriate mitigation measures. Physical barriers, like solar fences, elephant-proof trenches, stone, or rubble walls are installed as mitigation measures in all elephant-occupied habitats at the edge of the forest and human-use areas, globally. However, installations of the same without a proper scientific rationale and assessing and analysing their site-specific efficacy in reducing elephant incursion in the human settlement areas often fail in doing its intended objectives. It is important to note that humans are also a crucial component of conflict, hence research focusing on social aspects are essential for finding solutions. Keeping such concepts in mind, an assessment to determine the efficiency of two types of physical barriers, viz., solar fence and elephant-proof trench (EPT) was carried out in one of the prime elephant habitats of north-eastern India, in Golaghat district of Assam. Located on the southern bank of the Brahmaputra and home to Kaziranga National Park (KNP) on the west and Nambor-Doigurung Wildlife Sanctuary (NDWLS) in the south, Golaghat offers an ideal site for such study. It is realized that even after the presence of barriers in various areas of the district, conflict cases in the form of crop-raiding, human mortalities and human deaths continue to be reported. Handful studies on barriers and their effectiveness were done recently on the northern bank of Brahmaputra. However, no such appraisal on efficiency of barriers has been done in this landscape, where conflict levels are high. Hence, this study attempted to fill these existing research gaps.Item A Forked Relationship : Understanding the Acoustic Communication Strategies in Sympatric Drongos(Wildlife Institute of India, Dehradun, 2019) Lahiri, Sutirtha; Qureshi, Qamar; Kolipakam, VishnupriyaThe competitive exclusion principle states that ecologically similar species cannot co-exist and will either go extinct or develop diverging traits, the concept of environment filtering regards the environment. Patterns of trait divergence vary depending on whether the species occur in sympatry or in allopatry. Sympatry is defined as the co-occurrence of more than one species in the same geographical area with overlapping ranges. If closely related species occur in sympatry, competition is likely to shape divergence in their ecological as well as in the sensory domain, example acoustic signals. Diverse animal taxa employ acoustic signals for a variety of functions including mate choice, species identification, resource defence and other ecological and social functions. The primary aim of an acoustic signal is to efficiently communicate information over relatively long distances. This information, however, is subjected to changes and distortions imposed by the physical structure of the habitat, as well as masking interference from co-occurring signals of other acoustically communicating species. Masking interference by background noise or the simultaneously vocalization of other species- especially ones closely related- incur several disadvantages to the vocalizing individual. Signals with similar features have a high potential of interference for the species vocalizing, as well as for the receiver interpreting it. These disadvantages- or costs- could be the failure to respond to appropriate signals and the unnecessary response to territorial or mating signals not meant for them. However, a number of animals communicate successfully even in noisy and crowded environments, and can locate mates with relatively high success rates. This suggests the presence of powerful strategies to deal with the transmission, detection and recognition of relevant signals. To avoid acoustic competition due to the effect of masking interference, animals partition the acoustic resource in the temporal, spatial and spectral domains. Closely related species tend to be physically and behaviourally more similar than distantly related species, and are likely to possess similar songs and singing behaviour. The relationship between phylogenetic relatedness and trait similarity is investigated by quantifying what is called the ‘phylogenetic signal’- the tendency of related species to resemble each other more than is expected by chance. As a result, acoustic interference is likely to occur more often among closely related species, and they may evolve divergent signals to compensate. Drongos (Dicruridae) are a group of highly vocal passerines known for their vocal plasticity. There is a great extent to which their vocal repertoire can range in terms of diversity and function. Apart from having a wide range of species-specific repertoire, drongos are also mimetic species known to mimic the calls of conspecifics as well as other animals present in their environment. This study, conducted in Dehing Patkai Wildlife Sanctuary, Assam, focused on the four species of sympatric drongos- the Hair-crested Drongo, Lesser Racket-tailed Drongo, Greater Racket-tailed Drongo and Bronzed Drongo- and how they partition their acoustic niche. The study also looks into the ecological adaptations to counteract the impact of masking interference by habitat and closely related congeners. Active acoustic recording was done to record the four species of drongos in the study area. Line transects were walked along trails to calculate the density of each drongo species. Passive acoustic recorders were used to study the vocal activity patterns in the drongos. The study found evidence of overlapping acoustic niche between the drongos. However, they were significantly different from each other in the individual acoustic parameters. The drongos also occupied separate height classes, barring the lesser racket-tailed and the greater racket-tailed drongo. However, the drongos did not separate in their vocal activity pattern, suggesting overlap in the diel pattern. The study thus gives insight into the acoustic space of a group of highly versatile bird as well as the strategies they adapt to avoid interfering each other and thus co-existItem See Through Sound : Understanding the Pattern of Habitat use by Ganetic River Dolphin in the Kaziranga Part of Brahmaputra River(Wildlife Institute of India, Dehradun, 2019) Abhishek, B.; Qureshi, Qamar; Johnson, J.A.Studying the habitat and its associated features is important because of its driving factors that limits the abundance and distribution of a species. This study mainly focuses upon the abundance, distribution, activity and habitat use pattern of Gangetic river dolphins in part of the Brahmaputra River that flows through Kaziranga National Park. The abundance of Gangetic river dolphin and its relatedness to the different habitat features of the river and fish species were studied. The 92 km length of river in the study area was divided in to 43 segments, which were further broadly classified in to different river morphology.Item Assessment of Livestock Diseases as an Indicator of Risk to Greater One Horned Rhinoceros (Rhinoceros unicornis) in Manas National Park Assam(Wildlife Institute of India, Dehradun, 2013) Phukon, Debabrata; Nigam, Parag; Ramesh, K.Disease ecology is a fast emerging discipline in wildlife conservation. There is particular interest for mega herbivore-livestock interface issues. Diseases also play a role in structuring the demography and viability of the wild population, and this could be addressed by quantitative knowledge on the emergence, spread, persistence and evolution of infectious diseases. Re-introduced wild populations mimic the small population which are vulnerable to stochastic events and disease impacts. The present study focuses on reintroduced population of Greater One-homed Rhinoceros (Rhinoceros unicornis) and their sharing of habitat with livestock in Bansbari Range of Manas National Park (MNP), Assam. It was hypothesised that the interaction of rhinos with livestock has potential to contract diseases from the livestock population, and therefore the diversity and magnitude of disease prevalence in livestock is likely to pose serious threat to the rhinos. The study quantified disease distribution pattern and commonality between livestock and rhino population and map disease gradient in MNP during the period (Jan-April, 2013). The study design involved, (a) sampling of livestock for disease prevalence in the fringe villages, (b) mapping of zone of influence (ZO I) of livestock in the park by tracking livestock movement and sampling on systematic plots, and (c) analysis of livestock husbandry practices in the context of disease prevalence. A total of 110 dung and serum samples collected from 11 villages were Subjected to parasitological examination, disease diagnosis and screening for blood parasites. 10 transects were walked from the periphery to interior of the park and 46 plots were laid to quantify dung density distribution as a surrogate for disease risk. Rhino dung sample was collected from 9 fresh dung sites inside the park for screening of parasitic load and to understand the commonality between livestock and rhinos. The threat to rhino population was measured as an index, given by disease prevalence x livestock use intensity. Of the 110 biological samples collected from 110 livestock in 11 villages, 91 % of animals showed antibodies against one or other infectious agents. Serodiagnosis report confirmed the presence of antibodies against infectious diseases viz. Blue tongue, Tuberculosis, Brucellosis and Chlamydiosis, however were negative for Leptospirosis in livestock sampled. ZOI as measured from the fringe villages to forest interior ranged from 500m to 3.5kms (avg. dist. 2kms), and accounted for I9sq.kms. area. Interpolation results of dung density indicated significant variation of livestock use within ZOI, with high usage contributed by Gyatigaon followed by Katajhar and Rajabeel. Based on the dung analysis of rhinos, parasitic ova of Paramphistomum sp. and significant load of protozoan Balantidium coli was observed. The study established wide prevalence of disease in the livestock. Given that the ZOI of livestock in MNP includes home range of rhinos, the rhino population is likely to be under disease risk and conservation efforts needs to incorporate disease perspective for recovery efforts and long-term viability of rhinos in MNP.Item Social Behaviour and Duetting in Hoolock Gibbons in Gibbon Wildlife Sanctuary, Assam(Wildlife Institute of India, Dehradun, 2009) Sankaran, Sumithra; Rawat, G.S.; Kumar, R.S.The hoolock gibbon (Hoolock hoolock), only anthropoid primate found in India, is a pair-living, territorial species, which duets extensively. Various hypotheses regarding the function of this behaviour in monogamous primates include territory advertisement, pair-bonding, mate defense, resource defence and group cohesion. This study aimed to understand the nature of social behaviour of this species, and how duetting fits into the repertoire of social behaviour seen in this animal. Three groups of Hoolock gibbons were habituated and studied intensively over a three month period. Relationships between the different group members were explored, alongside time budgets of various activities of the adult pair, the synchrony in their behaviour and frequency and nature of all affiliative and agonistic behaviours. Relationships between territory sizes, group sizes, frequency of duetting and nature of other social interactions have been examined in detail. A considerable amount of individual difference were found between the different study animals in their interactions with other group members. These animals display complex affiliative interactions with rare displays of aggression. It was found that although the proportion of time spent in social interactions was comparable between the three groups, the proportioning of this total time among different social interactions may vary considerably. The primary difference was found to be in allogrooming interactions with the proportion of time time spent increasing with increase in group size. The study also found considerable evidence for the possible existance of male-care in this species.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.Item Food selection and ranging in hoolock gibbon (Hylobates hoolock Harlan 1834) in Borajan reserved forest, Assam(Wildlife Institute of India, Dehradun, 1997) Kakati, Kashmira; Sathyakumar, S.This study on food selection and ranging in the hoolock gibbon (Hylobates hoolock ,Harlan 1834) was carried out between December 1996 and April 1997 in Borajan Reserve Forest, a disturbed and fragmented patch of remnant tropical evergreen forest in Upper Assam, India. The hoolock gibbon is a primarily frugivorous species, confined to closed-canopy evergreen forests of North-east India, Bangladesh and Burma. This type is highly endangered in its entire range. Threats to the continued existence of the hoolock are from large-scale destruction of its habitat and hunting. Two troops of gibbons were followed intensively for four months and behavioural data were collected by continuous focal animal observations. Data were also collected ad libitum on a third troop. Data on the structural components of the vegetation and on the availability of food resources in the Intensive study area were collected systematically. The results of the study show that food availability influenced the diet, movement patterns, home-range sizes and behaviour of hoolock gibbons. Gibbons were selective in their diet using only forty-three plant species out of the more than two-hundred species present. Figs constituted important keystone resources for the gibbons. In months of low fruit availability, the gibbons had a predominantly folivorous diet. Home ranges were small (10.4 ha and 5.4 ha) and habitat degradation represents the greatest threat to the gibbons