M Sc Dissertation(WII)
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Item A Study on Breeding Behaviour of Oriental White-backed Vulture (Gyps bengalensis) in Anjarle and Deobag, Mahashtra(Wildlife Institute of India, Dehradun, 2011) Kambale, Asish Atmaram; Sivakumar, S.; Mohan, D.This study was aimed to understand the current status, distribution pattern, habitat characteristics, nesting success and nesting behaviour of Oriental Whitebacked vulture in the Konkan coast during a breeding season between December 2010 and May 2011. A total of 24 sites either nesting or feeding were located all along the Konkan coasts of Maharashtra during the survey using area search method as well as interview based techniques. Study shows that there was no significant difference in the habitats of both active and inactive nesting sites in the Konkan coast which indicates that the decline of nesting population of vulatures in the region may not be exclusively due to habitat destructionItem A Forked Relationship : Understanding the Acoustic Communication Strategies in Sympatric Drongos(Wildlife Institute of India, Dehradun, 2019) Lahiri, Sutirtha; Qureshi, Qamar; Kolipakam, V.The 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-exist.Item Resource Use and Distribution of Smooth-Coated Otter (Lutrogale perspicillata) in the Sub-Himalayan Foothill Rivers of Uttarakhand(Wildlife Institute of India, Dehradun, 2019) Basak, Sayanti; Hussain, S.A.; Gopi, G.V.Otters are the apex predators of the wetland ecosystems they inhabit. Being sensitive to both pollution and habitat destruction, the presence of otters in a wetland ecosystem, be it rivers, lakes, swamps, mangroves or estuaries, indicates the occurrence of a viable prey base, thus indicating an ecologically healthy condition of such ecosystems. Coupled with habitat, prey is one of the major factors that limit species populations. Many species, including otters, are often seen to cope up with disturbed surroundings only for the easy accessibility or abundance of prey in those areas. The aim of this study was to understand the ecology of Smooth- coated Otter (Lutrogale perspicillata) in terms of their habitat requirements, food habits, and distribution across the landscape. The study was conducted in select rivers of Rajaji National Park and Tiger Reserve, Lansdowne Forest Division, and Corbett National Park and Tiger Reserve. These protected areas fall in sub-Himalayan region, a region of high biodiversity value threatened by immense anthropogenic pressure. Habitat parameters were measured at every 250 m along a river bank and also in locations where there were otter evidences. The importance of different habitat parameters influencing otter occurrence were analysed using Generalised Linear Models (GLMs) and non-mapping technique using Bonferroni confidence interval approach. Smooth-coated Otter significantly preferred deep pools with moderate to sparse bank-side vegetation during the mid-winter and late-winter season. Moderate width water bodies are preferred over narrow water bodies. Muddy and sandy bank substrate types were preferred. Rocky stretches were largely avoided. Water body type i.e. pools and bank substrate type, i.e. rocky substrate, are the significantly influencing factors on otter distribution. Feeding habit of otters were studied by analysing 120 spraints collected throughout the study area. In this study, we also explored how the habitat suitability modelling could predict the percentage of area and a gradient of environmental conditions suitable for the occurrence of Smooth-coated Otter across the study area. MaxEnt modelling was used to predict habitat suitability of Smooth-coated Otter across the landscape. The most important variables affecting otter distribution were compound topographic index, Euclidean distance from the river, and slope position index. With increasing distance from water, and increasing slope, the suitability of an area to sustain otter populations decreased.Item Vigilance Architecture and Temporal Variation in Emergence-Return of a Keystone Bat : The Indian Flying Fox (Pteropus giganteus)(Wildlife Institute of India, Dehradun, 2019) Das, Pratik; Mondol, Samrat; Nair, Manoj V.The current study investigated the function of vigilance in terms of environmental vigilance (anti-predatory), social vigilance and environmental cues bats used to synchronize their emergence and return. I found that the Pteropus giganteus fruit bats showed varying levels of vigilance according to roosting architecture. Bats showed significant increase in environmental vigilance towards the periphery of the roosts (n=3), thus confirming the edge effect hypothesis. Bats however, displayed no significant variation with respect to guard effect or social vigilance as roosting positions were observed from periphery to core. Bats also displayed increasing social vigilance from core to peripheral areas of the roosting colonyItem Patterns of foraging in Olive Ridley Sea Turtle (Lepidochelys olivacea) Population on the East Coast of India and Habitat Characteristics of the Arribada Nesting Ground at Rushikulya(Wildlife Institute of India, Dehradun, 2019) Mudliar, Mohit; Sivakumar, K.; Gopi, G.V.; Shankar, KarthikThis study was conducted and aimed to explore the patterns of spatial segregation of foraging olive ridley turtles which nest on two distinct nesting areas of the eastern coast of India; secondly, to examine the characteristics of mass nesting ground of Rushikulya; and lastly, to assess the status of microplastic presence in mass nesting ground. The study found that the moisture contents and sand particle size were homogenous across the beaches of Rushikulya. The sandbar had most extreme values for four of the five studied habitat characters which might be due to surrounding waters. Sea turtles those stranded during December to February at Chennai as well as Rushikulya seems to be from a similar type of foraging areas as their carbon isotope ratio were not differentItem Investigating the Social Structure of Female Asiatic Lions(Wildlife Institute of India, Dehradun, 2019) Borah, Doli; Kolipakam, Vishnupriya; Jhala, Y.V.In this study the social structure of lion prides in the Gir landscape through behavioural observation discussed. the study was carried out in and around Gir protected area of Gujarat. In India the Gir forest only has the last free ranging population of Asiatic lion.Item Patterns of Bird Community Structure in Relation to Land-Use Driven Habitat Changes in the Arid Grasslands of Thar Desert(Wildlife Institute of India, Dehradun, 2019) Kher, Varun; Dutta, Sutirtha; Uniyal, V.P.; Page, Navendu V.The Indian Thar desert has seen a massive loss of grassland habitat in the last few decades. The main driver of this habitat loss has been the large-scale change in landuse from pastoralism to agriculture, leading to expansion of cultivated land over grasslands. This expansion, further compounded by a simultaneous rise in livestock population has drastically increased grazing pressure on the remaining rangelands. To complicate things further, irrigation schemes (notably the Indira Gandhi Canal) have led to intensification of agriculture in many areas. Protected area network in this landscape is minimal and ineffective, making the multiple-use agro-pastoral landscapes very important for conservation of wildlife. The largest protected area in the landscape – the “DNP WLS” – is also a multiple-use landscape and home to more than 50k people whose livelihood is tied to the federal mandate of conservation in the sanctuary. 1. Understanding the impact of land use change on native biodiversity is thus very important for conservation of biodiversity in this critical habitat. In this context, my study tries to find effects of land-use change on community structure of birds in the arid grassland of Jaisalmer district in the Thar Desert. 2. Understanding ecology or distribution and abundance of species is incomplete without holistically understanding the patterns and processes occurring at the community level. To this end, I explored the patterns of bird community structure in the Thar Desert and tried to understand how these properties change with land-use driven habitat change, by comparing fundamental properties of biological communities like species richness, abundance and composition. Additionally, I tried to find out potential habitat correlates of these properties, so as to shed some light on the processes that might be driving community assembly in response to land-use change. 3. Bird community structure: My results indicate that local-scale species richness,abundance and composition did not differ significantly between protected grasslands, rangelands and extensive rain-fed croplands, during either of the seasons. However, intensive irrigated croplands had a notably different community structure with higher species richness and abundance, during both winter and summer. The change is community structure of intensive croplands was influenced by the change in native species along with ingression of newly colonised species. Most of the newly colonised species were restricted to areas with intensive agriculture where their survival was potentially facilitated by the new microhabitats created by irrigation and associated changes (Rahmani & Soni, 1997). 4. Regional species pool: Intensive agriculture increased the overall species of birds in the region by sustaining newly colonised bird species; while the number of native species in this pool was only marginally lower than protected grasslands and comparable to all the other land-uses in both the seasons. Considering both the seasons together, protected grasslands had the highest naïve and estimated number of native species while the naïve and estimated number of native species in other three land-uses – Rangelands, extensive croplands and intensive croplands – was only marginally lower. This signifies that most species found in the region can use the entire gradient of land-use types at their current levels of intensification. Although this result by itself does not indicate that, all land-use types can sustain all the native species. 5. Seasonality of patterns: In winter, protected grasslands, rangelands and extensive croplands had similar bird communities, which together were significantly different from the communities in intensive croplands. The same pattern repeated in summer, but the magnitude of difference between bird communities in intensive agriculture and other land-uses was much lower. This pattern was correlated to the pattern shown by vegetation structure of intensive agriculture, which also became more similar to other land-uses after harvesting of crops in the summer. This potentially suggests that bird communities are influenced by vegetation structure and areas with similar vegetation structure would have similar bird communities. 6. Habitat correlates of species richness and bird community composition: In both the seasons, species richness was positively associated with the foliar volume of woody vegetation and negatively associated with forb volume (which in turn was negatively correlated with grass volume). During winter, species richness was positively related to crop volume and during summer, with compositional diversity of vegetation. Community composition like richness was influenced significantly by woody plant foliar biomass in both the seasons. Crop volume also had a significant influence on bird communities during both winter and summer, whereas grass volume was significantly influential only in winters. Conservation implications: This study corroborates many others in indicating that low-impact land-uses are important secondary habitats for conservation of grassland species (Dutta & Jhala, 2014; Wright, Lake, & Dolman, 2012). The inferences further support the commonly advocated approach of conserving grasslands at a landscape scale by strategically placing them as mosaics of low-impact agro pastoral land-use with small protected areas embedded within them (Dutta & Jhala, 2014; Dutta, Rahmani, & Jhala, 2011; Singh et al., 2006).Item Patterns and Determinants of Elephant Habitat Use in a Mosaic Landscape in Northern Chhattisgarh(Wildlife Institute of India, Dehradun, 2019) Meshram, Kushagra; Pandav, Bivash; Nigam, ParagHabitat use is affected by a wide range of factors,like the amount of resources available, its distribution in space, quality of resource,presence and absence of limiting factors like roads and settlements. Increasing anthropogenic pressure has lead to the degradation of the habitat available to animals in the form fragmentation of forests, introduction of invasive species and reduction in the quality of the available forage. This in turns alters the composition and modify the natural systems. This modification of habitat may compel animals to alter the way they use it by adopting new strategies. On these lines, I did my study on assessing the factors that influence habitat use of elephants in a mosaic landscape in Northern Chhattisgarh. The study was carried out in Surguja district of Chhattisgarh. This district is famous has been infamous for elephant conflict since 1900s. The problem has exacerbated due to rapid urbanisation, increasing population and alteration in land use. Today, it is one of the most human-elephant conflict affected area in country. This is a repercussion of wanton modification of natural habitat. How elephants are interacting with this modified habitat which is a matrix of remnant forest patches, agricultural areas and settlements is the crux of my study. In order to to study this, I selected a study area of 1200 square kilometres. As a part of the study I also followed two satellite Collared individuals(one living with a herd and the other, a solitary male) to understand spatiotemporal habitat use and ranging behaviour of elephants. I also collaborated with Indian Space and Research Organisation for my study. High resolution land-use maps were provided by ISRO for this study. The field work was carried out from 21st December 2018 to 15th April 2019. GIS based work was done in the GIS lab of the Wildlife Institute of India, Dehradun.Item Impacts of Road Related Disturbances on Mammalian and Vegetational Assemblages : A Case Study of SH-33 Passing Through Nagarahole Tiger Reserve, Karnataka(Wildlife Institute of India, Dehradun, 2019) Siva, R.; Habib, Bilal; Gubbi, SanjayUpcoming economies such as India need to strengthen their road network for the socioeconomic development of the country. While roads are important to the country, they are a threat to wildlife when they pass through the protected areas and other ecologically sensitive areas. Multiple impacts of roads on wildlife range from habitat loss, edge effects, vehicular traffic, pollution, animal mortality, barrier effect to invasion by alien flora and fauna. This project revealed the impacts of road-related disturbances on mammals and vegetation in Nagarahole Tiger Reserve, Karnataka. Mysore-Mananthavadi road (SH-33) is passing through the southern part of Nagarahole Tiger Reserve that has two segments in which one segment is decommissioned and another segment is closed for the vehicular traffic during the night. Here, I have compared the habitat use of mammals in these two segments using camera traps and assessed the impact of road-related disturbances on vegetation in this road by vegetation sampling. Vehicular density was estimated using the camera traps in these two segments.The study results revealed the avoidance of vehicular traffic segment by the mammals and activity pattern seems to be relatively unaffected by the vehicular traffic. It also shows the change in the vegetation composition and spread of invasive species due to road related disturbances.Item Impact of Habitat Fragmentation on Plant -Frugivore Interactions in Lowland Tropical Forests of Upper-Assam North East(Wildlife Institute of India, Dehradun, 2019) Jain, Abir; Page, Navendu; Rawat, G.S.Tropical forests are considered the storehouse of biodiversity. One of the key ecosystem processes that governs the diversity of tropical trees is seed dispersal. Tropical forests globally face deleterious effects of habitat fragmentation such as loss of habitat area, reduced species richness and altered community composition. Forest fragmentation can also alter mutualistic interactions between plants and seed dispersers, disrupting key ecosystem processes like seed recruitment and regeneration. In the past century, logging, habitat conversion to tea plantations and agricultural fields have resulted in the fragmentation of the last remaining lowland tropical forests of Upper Assam in north-east India. However, these isolated forest fragments might also hold a great potential to preserve native biodiversity distributed across patches. There is paucity of information on impacts of habitat fragmentation on plant–seed disperser interactions from Asia. 2. In this study, I investigate the impacts of habitat fragmentation on plant-disperser communities. The impacts were assessed at the level of the community and at the level of species guilds (body size, habits, and families). 3. The plant-frugivore interactions were recorded by systematically walking 27 trails across two habitat categories: contiguous forest sites (n=2) and fragmented sites (n=4) over the duration of four months. Spot census was carried out to record interactions between a fruiting plant and frugivores. Fruit handling behaviour of birds and fruit crop size of plants were also recorded. Plants and seed dispersers that interact with one another, forms a network. 4. I constructed presence-absence networks for each habitat type, which represents all plant-seed disperser interactions recorded in the contiguous forests and the forest fragments. ‘Network-level’ properties were obtained to understand the influence of fragmentation on plant-seed disperser communities and ‘Species-level’ properties were obtained to assess the roles of species guilds in each of these communities. 5. Although, the networks for contiguous and fragmented forests were similar in terms of total number of mutualist species participating in its organisation, their composition was different. On an average, frugivores had one plant partner more in the contiguous forest, while plants had three frugivore partners more in the forest fragments.