M Sc Dissertation(WII)

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

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Start date: 2011Subject: search.filters.subject.Species abundance

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    Assessing Ghost crab distribution, abundance and habitat use along the Coromandel Coast, Tamil Nadu
    (Wildlife Institute of India, Dehradun, 2025) Keerthi V; Gopi, G.V.
    Sandy beach ecosystems around the world are facing numerous threats and tremendous pressure due to ever increasing human population. One such threat, relevant to the Indian coastline, is the large scale plantations of shelterbelts of the exotic pine, Casuarina equisetifolia, which alters beach geomorphology. The effects of such plantations on permanent shore-dwelling organisms are poorly studied. Hence Ocypode crabs, the most conspicuous macro-invertebrate on sandy beaches, has been used as a model taxon to study the effects of different kinds of inland vegetation (Casuarina plantations, Mangrove plantations, native dune vegetation) on beach geomorphology and consequently, shore dwelling ghost crabs. The present study aims to - (1) Assess the density, distribution and demography of ghost crabs across treatments (2) Understand variations in habitat use and burrow architecture across treatments (3) Understand the effects of inland vegetation on beach geomorphology 2. A total of 24 transects, temporally replicated thrice each month between January 2025 - April 2025, were walked to estimate densities of ghost crabs using burrow counts as a proxy. 87 burrows across the treatments were cast using a mixture of Plaster of Paris and water and traits such as depth, diameter, shape and branching patterns were studied. Coast characteristics like slope, compactness, beach width, moisture and temperature were recorded at each study site. 3. Mean burrow densities and across shore distribution of Ocypode ceratophthalmus differed across the treatment types, with lowest densities in beaches adjacent to Casuarina plantations. This however wasn't statistically significant. The burrow structures also differed in complexity across treatments with the major drivers for this 7 difference being the size of the crab and the type of inland vegetation. Environmental variables were not found to have significant effects on burrow architecture. 4. The results indicate that the type of inland vegetation affects the population of ghost crabs through changes in beach geomorphology. Ghost crabs were also found to modify the structure of their burrows with changes in the habitat quality and environmental conditions, which gives insights into their adaptive capacities. The study, thus raises questions on the effects of certain management interventions, like the planting of shelterbelts on habitat quality and on the ecology of the species dwelling in the said habitats.
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    Estimating Abundance, Habitat Use, and Acoustic Characteristics of Irrawaddy Dolphins (Orcaella brevirostris) in Chilika Lagoon
    (Wildlife Institute of India, Dehradun, 2025) Sakshi; Kolipakam, Vishnupriya; Gopi, G.V.
    This study provides a comprehensive assessment of the Endangered Irrawaddy dolphin (Orcaella brevirostris) in Chilika Lagoon, India, through an integrated approach combining visual and acoustic surveys, environmental modelling, and prey availability analysis. Visual line-transect surveys and passive acoustic monitoring (using FPODs) were used to estimate dolphin abundance and explore patterns of habitat use. Dive-time observations revealed that calves and non-calves differ in their diving behavior, with non-calves exhibiting longer and more variable dive durations. Mark-recapture analysis produced corrected abundance estimates ranging from 24 to 32 individuals, with variation influenced by observer mismatches and brief surfacing events. To assess prey availability, catch per unit effort (CPUE) surveys were conducted at 22 sites in collaboration with local fishers. The highest CPUE values were recorded in the high salinity area (Outer channel) and low salinity area (Northern sector), indicating these areas may offer better foraging opportunities. Prey community sampling across 11 sites revealed spatial differences in species richness and evenness, with some locations dominated by a few taxa and others exhibiting high diversity. Richness estimators suggested that the true species count exceeds what was observed, indicating under-sampling in certain areas. Environmental modelling using a negative binomial generalized linear model showed that salinity had a significant negative effect on dolphin acoustic detections, while dissolved oxygen and depth were positively associated but not statistically significant. The frequency ranged from 20 kHz to 200kHz with a median frequency of 98kHz. The interclick interval ranged from 850 millisecond to 1010865 milliseconds with a median of 23605 millisecond. The histogram for ICI displayed a positively skewed distribution, consistent with irregular click trains interspersed with longer pauses. The findings highlight the importance of salinity and prey availability in shaping dolphin distribution in Chilika Lagoon. The results support targeted conservation actions such as regulating freshwater inflow, protecting productive foraging zones, and expanding acoustic monitoring efforts to improve long-term management of this vulnerable population.
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    Assessing the effect of anthropogenic disturbance on epiphytes in Khasi Hills of Meghalaya, India
    (Wildlife Institute of India, Dehradun, 2024) Nongrang, Tiewlyngksiar Lyngdoh; Kumar, Amit
    The key findings emerged from this study include- A total of 66 epiphytes comprising 32 species of orchids, 09 species of ferns, and 25 species of hemi-epiphytes & holo-epiphytes were recorded from the study area. Orchids had the highest species richness followed by ferns and hemi-epiphytes & holoepiphytes. Among orchids, species of Bulbophyllum, Pholidota and and a were dominant. The dominant species among ferns included Lepisorus sp., Davallodes hymenophylloides and Pyrrosia flocculosa whereas, among hemi-epiphytes and holo-epiphytes, the dominant species were Piper longum, Pothos chinensis, Rhaphidophora decursiva, Scurrula parasitica and Ficus sp. The abundance of epiphytes was observed highest in the Private Forest followed by the Village Forest and Reserve Forest. Species richness, using sampled-based Rarefaction curves of epiphytes showed that the curve is not reaching an asymptote and observed species were highest in the Village Forest followed by Reserve Forest and Private Forest. The most abundant groups of epiphytes in Private Forest were hemiepiphytes mainly dominating on the lower trunk. In the village forest, orchids were found occupying the inner canopy. In Reserve Forest, ferns were in abundance and occupied the upper trunk. Species correlation shows no difference in species composition. Environmental variables are factors that can explain the difference in species richness and abundance of epiphytes.
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    Abundance and social organization of male Asian elephants (Elephas maximus) in Rajaji Tiger Reserve
    (Wildlife Institute of India, Dehradun, 2024) Madhusudanan, Abhimanyu; Pandav, Bivash; Lakshminarayan, N.; Mondol, Samrat
    1. Asian Elephants are complex, social, and polygynous mammals living in fission-fusion societies. Male elephants are known to alternate between leading solitary lives, in all-male groups or associating with mixed-sex herds. All-male groups allow younger males to learn from older males, test strengths and spar with their peers. While much work has been done on female Asian elephant societies, studies focused on male association patterns are limited, but gaining importance in the light of human-elephant conflicts. In this study, I estimated the abundance of adult male elephants in a stretch of forest spanning over 40 km along the east bank of the river Ganga in Uttarakhand using a polygon search-based spatially explicit capture recapture (SECR) framework 2. I invested a survey effort of ~3014 km to estimate the abundance of the adult male segment of the population using a capture-recapture framework. Using a combination of morphological features, I identified 34 adult males from 124 elephant sightings. Association patterns of the male elephants, following behavioural sampling approaches were also recorded during the surveys. 3. Adult male elephant density was 0.05 (SE=0.01)/km2, and a derived abundance of 40 (SE=1.4) for the 475 km2 study area. This demonstrates that polygon search-based SECR is an effective approach in estimating elephant abundance.
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    Responses of Wild Ungulates to Anthropogenic Pressure and Perception of Local Communities Towards Conservation of Wild Ungulates in Dampa Tiger Reserve, Mizoram India
    (Wildlife Institute of India, Dehradun, 2021) Chakama, Joonu; Sathyakumar, S.; Kawlni, Lallaianpuii; Kolipakam, Vishnupriya
    With the increasing anthropogenic pressures, conservation of ungulates is ever more crucial as they help in maintaining the forest structure. The impact of anthropogenic pressures such as hunting of wild ungulates by local communities in Mizoram, India, is limited and lacks reliable information. This study was conducted in Dampa Tiger Reserve (DTR), Mamit district, Mizoram from January-Mid May, 2021 to quantify the responses of wild ungulates to the anthropogenic pressures, as a measure of conservation efforts. This study focussed on the population and distribution of ungulates in Dampa Tiger Reserve (DTR), Mizoram and assessed how the ungulates responded to human use areas. Stratified systematic sampling was done in an intensive study area (40 km2) to assess the ungulate density, distribution and activity pattern. In addition to that, the perception and attitude of local communities towards wild ungulates were also assessed. Estimates of the distribution, population and activity pattern of ungulates were obtained using single season occupancy model and cameratrap based distance sampling method whereas the local people perception and attitude were analysed based on answers from the semi-structured interview. The study was carried out on the Teirei and Phuldungsei range of the DTR. A total of 40 grids (1 km2 each) were sampled following the above framework. The grids were sampled using Camera-based distance sampling for population estimation in which the cameras were placed at the centroid of the grid. The density of the ungulates in two areas (high and low human use) could not be compared as the anthropogenic disturbance was homogenous throughout the study area. However, the pooled density of wild pig (0.55±0.23) was the highest among the other species, followed by barking deer (0.28±0.06) and sambar (0.20±0.09). The activities of the ungulates were at the peak from the crepuscular period to early morning and late evening. Occupancy pattern showed that barking deer distribution was influenced by the food availability/ground cover including areas near human habitations whereas sambar occurrence was negatively influenced by non-forest and presence of anthropogenic disturbance. Perception survey revealed that villagers showed positive perception towards ungulate conservation, however, in contrast to these responses, conservation practices in DTR by the local communities still lacks as intensive hunting still prevails. This study highlights the impact of anthropogenic pressure towards ungulates and how strengthen management interventions is necessary to ensure the conservation of ungulates in DTR.
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    Influence of Forest Cover on Fruit and Frugivore Richness and Abundance in Southern Western Ghats
    (Wildlife Institute of India, Dehradun, 2021) Takorbhai, Patel Zankhnaben; Page, Navendu V.; Kumar, Amit
    Habitat fragmentation is a pervasive threat to ecosystem processes like seed dispersal, which is vital for biodiversity maintenance in tropical forests. Habitat fragmentation negatively impacts the richness, abundance and composition of plants and animals, thereby disrupting the interactions between them, with cascading impacts on biodiversity. However, the remnant fragments continue to harbour biodiversity. However, it is critical to determine the functional value of the fragments in terms of fruit resource diversity and availability and prevalence of frugivores across different size classes. To this end, I conducted the study in the Valparai plateau and adjacent contiguous patches of rainforests in the Western Ghats. I first determined the organization of plant-seed disperser community and identified key frugivores and plants in the landscape using network analysis. Using mixed models and the recently developed Joint Species Distribution Modelling approach called HMSC (hierarchical modelling of species communities), I investigated 1) the relationship between the amount of forest cover and richness of fruiting plants across different seed size classes, 2) the relationship between the amount of forest cover and availability of fruit s across different seed size classes 3) the relationship between richness and presence of all the avian frugivores and, amount of forest cover, and richness and availability of fruits. I recorded the frugivores and fruiting plants from 33 trails distributed in 12 fragments and 2 sites in contiguous area during four months of sampling. I also recorded plant-frugivore interactions. I documented 49 species of fruiting plants and 17 species of avian frugivores
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    Comparative Analysis of Abundance Estimation Methods for Ungulates Along with their Spatio-Temporal Interaction and Habitat use in Pakke Tiger Reserve, Anunachal Pradesh
    (Wildlife Institute of India, Dehradun, 2021) Singh, Tarun; Kolipakam, Vishnupriya; Qureshi, Qamar; Sathyakumar, S.
    Abundance estimation and habitat utilization of species are critical for the conservation of any species. The forests of North-Eastern India are challenging due to the low abundance of ungulates, dense undergrowth, and logistic feasibility. In this study, we attempt to use camera trap-based methods (distance sampling and random encounter model) to estimate the abundance and habitat use of five ungulate species in the Pakke Tiger Reserve of western Arunachal Pradesh. This study was conducted from February 2021 to May 2021.This study provides crucial information on abundances and habitat use, which can be used for focussed conservation efforts for ungulates occurring in low densities.
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    Diversity and abundance of birds in disturbed and undisturbed wetlands of Manipur river basin
    (Wildlife Institute of India, Dehradun, 2017) Sharma, Sijagurumanyum Rohikanta; Hussain, S.A.; Nair, Manoj V.; Tuboi, Chongpi
    The Northeast (NE) Indian region is one of the hotspot of Indo Malayan biodiversity that remains largely unexplored. For this study, two wetlands in the NE Indian region of Manipur, viz Keibul Lamjao National Park (KLNP) and Pumlen pat (PP) were selected as the study site. Diversity and abundance of bird species in the region were assessed because of their prominence in the landscape. Conservation measures are needed for both the sites In tenns of these threatened bird species. Site-specific management strategies need to be incorporated in the management plan for the management of the isolated local populations of Black-breasted Parrotbill and Yellow-breasted Bunting in the undisturbed site (KLNP). Whereas some legal conservation measure is needed for conserving threatened grassland birds in the disturbed site (PP). It is also mandatory to monitor the population of Yellow-breasted Bunting population discovered from both the sites.
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    Ecology of Leopard (Panthera pardus) in Sanjay Gandhi National Park Maharashtra with Special Reference to its Abundance Prey Selection and Food Habits
    (Wildlife Institute of India, Dehradun, 2015) Surve, Nikit; Sathyakumar, S.; Sankar, K.
    Though information is available on the leopard's ecology from natural habitats, very less information is available on the ecology of leopards from human-dominated habitats in India. Hence the study was conducted at Sanjay Gandhi National Park (SGNP), Mumbai where leopard was found to be the apex predator. The total area of SGNP is 104 sq.km. It is covered , by human habitations on all the sides leaving just a narrow tip on the northern side. Camera traps were deployed in a systematic manner covering the entire study area to get leopard images. Leopard density of 21.55 ± 4.6 (SE) at 95% confidence interval was calculated in the study area using Spatially Explicit Capture Recapture models. The wild prey densities were estimated inside SGNP using 'Distance sampling with the help of line transects. The , maximum density amongst ungulates was shown by chital (14.49 ± 5.2[SE]) followed by sambar (7.52 ± 1.7[SE]). Among primates, maximum density was shown by common langur (48.04 ± 8[SE]) followed by bonnet macaque (30.78 ± 12[SE]). Density for other prey species encountered on line transects like wild pig and barking deer were not estimated as they were sighted only twice on the line transects. Dog density on the periphery of SGNP was ca1culated to be 17.26 ± 0.69 (SE) using mark-recapture technique. Food habits of leopards were studied by conducting dietary analysis using leopard scat. The high density of dogs in the periphery of the National Park also reflected in the leopard's diet. Dogs alone contributed 24.46 % of the total biomass consumed in leopard's diet. Domestic prey contributed to 43% whereas wild prey contributed to 57 % of leopard's diet in terms of relative biomass consumed. The study suggests that the leopards are dependent on both wild as well as domestic prey in the study area. Leopards can coexist with humans even amidst urban environs as long as prey population (both domestic and wild) remain sufficient and their habitat is protected.
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    Effect of Inter-Habitat Matrix on Tropical Evergreen Forest Remnants : An Emprical Test of Matris-Tolerrance Hypothesis on Butterflies
    (Wildlife Institute of India, Dehradun, 2013) Kumar, Deepak C.; Talukdar, Gautam; Habib, Bilal; Kunte, Krushnamegh
    Recent studies on habitat fragmentation has highlighted the importance of inter-habitat matrix and the need for a shift from traditional binary perspective to a 'matrix composition' ·perspective for understanding species diversity patterns in human modified landscapes . Matrix-tolerance model provides a simple framework for understanding the sensitivity of species to fragmentation by simultaneous study of native forest patches and surrounding matrix. According to this model, abundance of a species in the matrix is inversely proportional to its vulnerability to fragmentation. This study tested the matrix-tolerance hypothesis on butterflies of tropical evergreen forest remnants, surrounded by a matrix of coffee plantation and paddy field in Kodagu region of Western Ghats. Western Ghats is rich in butterfly fauna represented by 333 species of which 33 are endemic to the biogeographic region. The region is also characteristic in having human modified habitats with relatively large proportion of native forest patches which calls for a landscape level approach for conservation. In order to test the matrix tolerance hypothesis sampling was carried out in 16 sites which included 7 in fragments (sacred groves), 7 in matrix (5 in coffee plantations, 2 in paddy field) and 2 in large contiguous forest (Reserve Forest). For abundance estimation of butterflies, time constrained surveys were carried out 3 times in each site between January 10 and April 8, 2013. An index related to fragmentation vulnerability was generated for each species using abundance data obtained from time-constrained surveys. The Fragmentation Vulnerability Index, FVI was defined as the ratio between average abundance of the species in the fragments and average abundance in the continuous patch. Spearma'n's rank correlation was then used to test the association between rank FVI and rank matrix abundance. Various microclimatic and habitat variables were measured in matrix sites and Generalized Linear Models (GLMs) were constructed to test their association with estimated species richness. Analyses were carried out using SPSS 16 and R (version 3.0.1, R core team 2013) software. The present study shows that the relation between abundance of species in the inter-habitat matrix and its vulnerability to fragmentation is positive and significant (rs= 0.514, p = 0.001, N = 37). Species which are capable of tolerating the matrix are found to be less vulnerable to fragmentation. Some species deviate from the expected model in their response to habitat fragmentation which could possibly be explained by examining species specific traits. Fragment size didn't have a significant effect on relation between matrix abundance and fragmentation vulnerability index (F=0.758, p=0.387, df=l), unlike expected from previous studies. This could either be due to smaller range of fragment sizes in the present study or due to confounding factors like patch isolation and patch quality which can mask the effect of patch size. Among various habitat 'and microclimatic variables, canopy cover was found to be 'important predictor of ciliated species richness in matrix sites (weight = 0.8, ~ = 0.8, P = 0.008). Coffee plantations generally have a moderate level of canopy cover which is favorable for most butterfly species. But compared to paddy field~ the canopy cover is higher in coffee plantations and this could be the reason for increase in species richness with increasing canopy cover in matrix sites.