Theses and Dissertations

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Start date: 2020Subject: search.filters.subject.Birds

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    Status, habitat use and factors affecting breeding waterbirds of Changthang Wildlife Sanctuary, Ladakh (India).
    (Wildlife Institute of India, Dehradun, 2020) Mahar, Neeraj
    Tourism has evolved as an alternative livelihood for the local people and has reduced their direct dependencies on natural resources and perhaps indirectly contributed towards nature conservation. However, unregulated tourism activities have led to degradation of natural systems and increased the ecological vulnerabilities of local communities. Often, tourism and other developmental activities related disturbances collide with the peak season for several biological processes and affect the ability of natural system to revive and restore itself. In case of waterbirds these disturbance affect the breeding success. Other than anthropogenic activities, domestic dogs, apparently the most abundant carnivores in the world, pose a major threat to local wildlife. Recent studies have determined waterbirds as an important part of their diet. The existing literature clearly suggested that there was a huge information gap regarding Trans-Himalayan wetlands and their avifaunal characteristics. Previous studies were either site specific or species-specific, and thus, landscape level base line data was either scanty or unavailable. The Trans-Himalayan wetlands of India are increasingly under anthropogenic stress which is affecting their ecological structure and functions, especially the breeding birds. Blacknecked crane (BNC) is one of the flagship species of these wetlands. With the above background, I decided to study and understand their ecology and major threats faced by waterbirds and wetlands of Changthang Wildlife Sanctuary (CWLS). The objectives for this work were to (1) assess the population status and habitat use by waterbirds, (2)evaluate the factors affecting the breeding waterbirds, and (3) assess change in the wetland area.
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    Patterns of distribution and multiscale-habitat correlates of riverine birds in the upper Ganges, Western Himalaya.
    (Wildlife Institute of India, Dehradun, 2021) Sinha, Ankita; Ramesh, K.; Jayapal, R.
    Fauna associated with riverine ecosystems vary considerably at the global scale ranging from obligate terrestrial to obligate aquatic. Birds constitute key components of wildlife along running water systems. 2. The global river bird community is diverse with 66 species, spanning across 19 families with 37 non-passerines and 29 passerines. Asia has the maximum number of species followed by South America and Africa. 3. The global distribution ranges of specialist river birds show that large areas of the world hold few or no specialist riverine birds. Richness peaks in the eastern Himalaya and the Myanmar-China border, around the Kakabo Raazi mountains where more than 15 species of specialist river birds overlap in range. 4. Species richness reflects considerable radiation in particular groups; Muscicapidae (small passerine insectivorous birds mostly belonging to the old world) in Asia, ovenbirds (Funariidae) and tyrant flycatchers (Tyrannidae)in South America, and the Pratincoles (Glareolidae) in Africa. 5. Ecological understanding and conservation efforts of specialist river birds remain rudimentary especially in the tropics where rivers are faced with a host of threats. 6. In this particular study, field surveys were undertaken to understand bird community composition and river habitat characteristics across summer (breeding) and autumn (wintering/non-breeding) seasons in the Bhagirathi basin, a major headstream of the Upper Ganges in the state of Uttarakhand in the western Indian Himalaya between years 2014 and 2018.
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    Population dynamics of the Edible-Nest Swiftlet Aerodramus Fuciphagus Inexpectatus in the Andaman Islands
    (SACON, 2024) Prathamesh, H.G.; Manchi, Shirish S.
    Population dynamics play a fundamental role in ecological research and have important implications. It refers to the study of how the size and composition of populations of organisms change over time and in response to various factors such as birth and death rates, immigration and emigration, environmental conditions, resource availability, and interactions with other species. Many researchers have long studied terrestrial avian population dynamics; however, birds in hypogean environments, such as the Edible-nest Swiftlet, did not receive much attention. The Edible-nest Swiftlet (Aerodramus fuciphagus inexpectatus) is a cave-dwelling bird studied primarily in ex-situ habitats due to its economic importance. The studies in wild or urban areas majorly focus on breeding biology, ecology, habitat, and population trends. However, many aspects of population dynamics are never attempted due to a lack of resources and practical difficulties, such as in the Andaman Islands. Therefore, this study aims to investigate the population dynamics of the Edible-nest Swiftlet in the Andaman Islands. The study aims to investigate the various aspects of population dynamics: site fidelity, colonial sex ratio, and inter-colonial dispersal patterns, considering the biotic and abiotic factors influencing these traits. The study overall intends to provide valuable insights into the swiftlet’s research and conservation.
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    Patterns of Avian Diversity in different land-use and forest patch size of Kumaon Himalayas, Uttarakhand
    (Wildlife Institute of India, Dehradun, 2021) Arya, Sumit Kumar; Gopi, G.V.
    The present study was conducted in the Pithoragarh districts of the Kumaon Himalayas in Uttarakhand. The point count method was performed in matrices of agriculture land and forests of the lower Pithoragarh district to assess bird diversity patterns in different land use, habitat types, and disturbance regimes. A multiscale landscape heterogeneity approach was performed for determining the impact of forest patch size and vegetation structure on bird diversity. For assessment of the seasonal changes in the bird diversity pattern, a village ecosystem was monitored in the landscape.
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    Seasonal Pattern in Habitat Selection by Birds of Jhimil Jheel Conservation Reserve Uttarakhand
    (Wildlife Institute of India, Dehradun, 2022) Das, Ankita; Ramesh, K.
    The present study was initiated to assess seasonal pattern in habitat selection by birds in Jhilmil Jheel Conservation Reserve (JJCR) which is a small-sized Protected Area (PA). This work also focuses on both ‘process’ and ‘pattern’ of bird community structure. The work also focusses on how small-sized PAs are equally important in conserving wildlife species such as birds. Understanding the relationship of birds with habitat provides insights into habitat use, which contributes in the conservation of species. Habitat selection of birds is one of the foremost steps to understand the complexity of their community. Some factors influencing habitat selection are habitat heterogeneity, structure and composition of vegetation, seasonality and co-occurrence. Habitat heterogeneity helps in maintaining high bird diversity. Abundance and distribution of species in a community also depends on the physiognomic, floristic composition of the forest vegetation and seasonality. For the present research work, the study area was stratified into six habitats: plantation, mixed deciduous forest (mixed forest), riverine habitat, scrub forest, grasslands and agriculture fields-human settlement.
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    DIVERSITY AND DISTRIBUTION OF BIRDS IN BHARATHAPUZHA RIVER BASIN, KERALA
    (SACON, 2024) P N , Anoop Raj; Kumara, H N
    Bharathapuzha also known as the Nila River is the second-longest river in Kerala. It is considered as one of the most important rivers in Kerala for its ecological, cultural, and historical importance. Thus, it is known as the cradle of civilisation in Kerala. This river originates from the northern and southern rims of the Palakkad Gap. It flows towards the west through the Coimbatore district in Tamil Nadu and the Palakkad, Thrissur, and Malappuram, districts of Kerala before draining into the Arabian Sea. The river's total length is 209 km with a drainage area of 6186 km2. Chitturpuzha, Kalpathipuzha Gayathripuzha, and Thoothapuzha are major tributaries of this river. Birds are considered as indicators of habitat quality. They play an important role as predators, prey, pollinators and scavengers in nature. Understanding the natural bird assemblage, its patterns, and its process will help prioritize the potential conservation areas. Many researchers have attempted to study bird communities in the different habitats in the Western Ghats. Their observations on birds provided useful information to understand the distribution trend of birds. Most of such studies focused on the forest ecosystems in the protected area network. Understanding the distribution pattern of birds and their drivers in highly disturbed ecosystems outside the protected area network is less attempted. From the origin to the mouth, the river passes through various ecosystems and topographic conditions. Bharathapuzha originates and runs through forest ecosystems in the Western Ghats hill ranges initially, then travels through various human habitations, and agrarian lands and finally reaches the Arabian Sea. So, it supports bird communities of different forest ecosystems, agrarian lands, water bodies, and human habitations including the urban areas. Most of these ecosystems are located outside the protected area network and are vulnerable to anthropogenic pressures. Deforestation in the hill region, construction of check dams, indiscriminate sand mining, the spread of weeds and invasive plants inside the river channel, expansion of monoculture plantations, encroachment and water pollution are the major threats to the river ecosystem. This study attempted to understand the patterns of avifaunal assemblage in the Bharathapuzha river basin which is highly disturbed due to anthropogenic pressures that destroyed the riverine habitats, water quality, and natural water flow.
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    Foraging ecology of Great-Slaty Woodpecker in and around Pawalgarh Conservation reserve in Western Himalaya
    (Wildlife Institute of India, Dehradun, 2024) Kaur, Sarabjeet; Gopi, G.V.; Uniyal, V.P.
    The Great Slaty Woodpecker (Mulleripicus pulverulentus, Temminck 1826) is an old-world woodpecker that prefers mature and old-growth dipterocarp forests (including Shorea robusta, Sal) across its known distribution range. The study reveals population demography, the social system and foraging behavior from logged forest and infer the distribution and home range of the Great Slaty Woodpecker, a cooperative breeding bird species, in and around the Pawalgarh Conservation Reserve in the western Himalaya of Uttarakhand state. This study presents the first census conducted for the Great Slaty Woodpecker, providing an ecological baseline for the species population estimation from its known distribution range. I inferred the home range size of each group based on 161 independent sightings of 11 family groups. These sightings represent behaviors such as foraging, nesting, roosting, vocalizations, and territory defense
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    Effects of Local- and Landscape-level Drivers in Influencing Bird Diversity and Persistence in Cashew Plantations of the Northern Western Ghats
    (Wildlife Institute of India, Dehradun, 2024) Madhu, Nandita; Jayapal, Rajah; Page, Navendu V.; Naniwadekar, Rohit
    Agricultural expansion is a significant driver of deforestation and biodiversity loss, particularly in the tropics. The Western Ghats-Sri Lanka biodiversity hotspot is no exception. Most forest patches in the northern Western Ghats are being cleared for cashew cultivation. However, here, cashew plantations host varying proportions of cashew and native trees and have varying extents of ambient forest cover. Investigating the effects of such local and landscape-level drivers across land use types on taxonomic, functional, and phylogenetic diversities, as well as species- and trait-specific responses of birds, as implemented in this study, can give comprehensive insights on the impacts of forest conversion. I conducted this study in the low-elevation forests and cashew plantation landscape of Tillari, Maharashtra. I compared tree species diversity and vegetation structural attributes across land use types using Hill-Shannon diversity and linear models (LMs). To assess how land use type affects bird species composition and taxonomic diversity, I used non-metric multidimensional sampling (NMDS) and Hill-Shannon diversity. To compare functional and phylogenetic impacts across land use types, I used SES (Standardised Effect Size) values of fMPD (functional Mean Pairwise Distance) and pMPD (phylogenetic Mean Pairwise Distance) for LMs and Tukey’s post-hoc analysis. Using Hierarchical Modelling of Species Communities (HMSC), I looked for 1) bird species responses, 2) trait responses, and 3) a phylogenetic signal in the residuals. I collected bird and vegetation data from 100 points distributed across forest, mixed cashew plantations, and pure cashew plantations. My field collaborator (Vishal Sadekar) and I sampled vegetation within a 10 m radius of circular plots around all points. We sampled birds, implementing 10-minute point counts at a point, replicated 5 times across 4 months between January to May 2024. Vegetation differed significantly across all three land use types in terms of tree species diversity and tree height, where the forest had the highest estimates followed by mixed cashew. NMDS showed that the community in mixed cashew plantations overlapped with that of pure cashew plantations. There was no significant effect of land use type on functional diversity. But taxonomic and phylogenetic diversities were lowest in pure cashew. The HMSC model revealed a low explained variation (Tjur R2 = 0.1372), but I found land use type, a site-level variable, to exhibit the highest explained variation of 58% compared to the landscape-level variables. Forest species like Malabar Trogon (Harpactes fasciatus) and Black-naped Monarch (Hypothymis azurea) responded negatively to mixed and pure cashew plantations. Species like Golden-fronted Leafbird (Chloropsis auriforns) and Tickell’s Blue Flycatcher (Cyornis tickelliae) benefitted from mixed cashew and open country species like Indian Peafowl (Pavo cristatus) and Plain Prinia (Prinia inornata) responded positively to pure cashew. Trait response analysis revealed that evergreen species responded positively to the forest and negatively to both cashew habitats. Sedentary species responded positively to forest cover in 800 m. No evidence of a phylogenetic signal was found in the residuals (⍴ = 0.23, 95% CI: 0 - 0.68). This study highlights the value of mixed cashew plantations which are more habitable than pure cashew plantations due to native tree prevalence. However, this study also emphasises that even mixed cashew plantations cannot replace forests as habitats for evergreen forest species. This message is now more crucial than ever in the light of ongoing forest clearance in the northern Western Ghats.
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    Leveraging citizen science for bird monitoring: A case study assessing the impacts of urbanization on bird assemblages of the Nilgiris
    (Wildlife Institute of India, Dehradun, 2024) Phinehas N, David; Kher, Varun; Robin, V.V.; Jha, Ashish
    Anthropogenic alteration of habitats is the leading cause for biodiversity loss across the world. To accommodate the ever increasing human population, intensification of urbanised areas have led to the most extreme forms for habitat alteration (Batáry et al., 2018) and imposes a unique set of ecological filters. 2. Over that last 2 centuries during the colonial past, the Nilgiris has witnessed large-scale change in the landscape structure from native shola-grassland matrix to extensive tea and eucalyptus plantations. Currently it has emerged into a tourist haven, attracting millions every year, leading to expansion of the urban cover to accommodate the growing demand. 3. This study illuminates the profound effects of urbanization on bird communities in the Nilgiris, showcasing how habitat transformation alters community parameters such as, species richness, abundance, and composition. My results indicate a stark pattern: as urbanization intensifies, species richness declines, while a select few generalist species thrive in high abundance. 4. My findings reveal that settlements and proximity to remnant shola patches are the primary factors influencing avian community structure. Areas with higher settlement percentages and greater distances from shola patches exhibit reduced species richness and diversity. In contrast, less urbanized areas, closer to natural habitats, maintain higher biodiversity. This aligns with the hypothesis that urban environments simplify habitat structures, creating 'filter' that only a limited number of species can pass through, thereby fostering biotic homogenization. 5. Urban generalists, such as the House Sparrow, Rock Pigeon, and House Crow, flourish in highly urbanized zones due to their ability to exploit the abundant food resources and nesting sites provided by human activities. These species benefit from the homogenized urban landscape, which offers ample opportunities for foraging and nesting, often at the expense of more specialized species. Conversely, endemic shola forest specialists, such as the Nilgiri Laughing thrush and the Black-and-orange Flycatcher, suffer due to their stringent habitat requirements and limited dispersal abilities. These findings highlight the ecological trade-offs imposed by urbanization, where habitat degradation and loss disproportionately impact species with narrow niche widths. 6. This study also highlights the usefulness of citizen science as a tool for collection of largescale data in a short time span. I also tested for the accuracy of the citizen science data against a research-grade benchmark, ie, data collected by me. The results suggest that no significant variations were detected between the two datasets. 7. Conservation Implications: Monitoring species with vulnerable traits to keep track of further degradation of the habitat and involvement of the local citizens is needed. The study highlights a critical need to preserve remaining shola fragments and implementation of biodiversity friendly urban planning.
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    The effect of disturbance-induced changes in vegetation structure and arthropod abundance on mixed-species bird flocks in the oak forests of the Western Himalaya
    (Wildlife Institute of India, Dehradun, 2024) Satish, Aditya; Page, Navendu; Bangal, Priti; Shahabuddin, Ghazala
    Mixed-species flocks are an interactive group of insectivorous birds that forage together and move in the same direction. Flocks provide foraging and anti-predatory benefits to participants. Habitat disturbance may affect flocks by – a) altering presence or abundance of participating birds in the community or b) altering flocking propensities of species. 2. I investigated the effects of habitat disturbance on flocks in the Western Himalaya of Uttarakhand, India. Disturbance was mediated through two mechanisms – changes in vegetation structure and arthropod abundance (food availability). I examined how these environmental variations impacted flocks at a community level through changes in flock richness, flock size, number of flocks encountered and flock composition. I also explored how flocking propensity (a species-specific tendency to join flocks) is impacted by these variables. 3. Flocks are a subset of the insectivorous bird community. I found that insectivore richness and abundance decreased with reduced structural complexity of vegetation caused by disturbance. Reduced structural complexity also led to a corresponding decline in flock richness, size and number of flocks encountered in disturbed sites. With regards to variation of flock composition with disturbance, I found no clear species-composition-based clustering in transects with similar disturbance levels. 4. There seems to be an interactive link between arthropods, insectivorous birds and disturbance. Disturbance was correlated with strong declines in foliage arthropod abundance, which in turn contributes to lower insectivore richness and abundance. Flying arthropod abundance largely remained constant with disturbance, so I would like to draw 2 attention to the effect of foliage arthropod abundance on flock variables in the following sections. 5. The number of flocks encountered increased with foliage arthropod abundance. Since insectivores in undisturbed sites are supported by a larger prey base, the higher frequency of flocking may be correlated to the larger pool of insectivores that are available to flock at a given time. I did not find significant effects of foliage arthropod abundance on flock richness and flock size. 6. I found that flocking propensity of the three most common species (Gray-hooded Warbler, Black-throated Tit and Green-backed Tit) in flocks showed a declining trend with higher disturbance. I also observed that the propensity of these species showed an increasing trend with higher foliage arthropod abundance. However, none of these relationships were statistically significant. More detailed research is recommended to investigate these preliminary patterns further, to better understand the complex interactions between propensity, disturbance and food availability. 7. To conclude, disturbance was found to have a negative impact on mixed-species flocks, primarily by altering the presence and abundance of insectivorous birds. From a habitat perspective, insectivores suffered declines due to the simplification of vegetation structure. Insectivores also face food scarcity as foliage arthropod abundance decreases. The combined effect of habitat loss and reduced food availability in disturbed sites leads to lower insectivore richness and abundance, which is in turn reflected in fewer, smaller and more species-poor flocks.