Theses and Dissertations

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    Diversity and structure of butterfly assemblages along altitudinal gradient in Tons valley, Western Himalaya
    (wildlife Institute of India, 2013) Bhardwaj, Manish; Uniyal, V.P.; Singh, Arun Pratap
    Present study reveals the distribution pattern of butterflies along elevation gradient along the Tons river valley in the western Himalaya. Two protected areas lies with current study area viz. Govind National Park and Govind Wildlife sanctuary and the rest of the area lies within any formal category of protection. The area represents high elevational variation (900 – 6316 m) and a gradient of disturbance regimes and from natural Himalayan forests to highly disturbed villages and agricultural lands. Current study document patterns and processes involved in shaping diversity and distribution of butterflies along an elevation gradient in Tons valley. This study provides a baseline faunistic inventory of the diversity of butterflies including description of general identification features, their relation to classification and subfamilies and genera of butterflies sampled from the Tons valley during more than four years of observations from April 2008 to October 2012. A total of 189 species representing 98 genera in 5 families were recorded in Tons valley during entire sampling period.
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    SEASONALITY AND ABUNDANCE OF INSECTS WITH SPECIAL REFERENCE TO BUTTERFLIES (LEPIDOPTERA: RHOPALOCERA) IN A MOIST DECIDUOUS FOREST OF SIRUVANI, NILGIRI BIOSPHERE RESERVE. SOUTH INDIA
    (SACON, 2000) Arun, P R; Vijeyan, V S
    The present study describes the seasonal variations in the abundance of insect groups in a natural moist deciduous forest of Western ghats, South India. The study covers the seasonal abundance patterns of six major insect orders, namely Coleoptera, Lepidoptera, Hemiptera, Diptera, Orthoptera, and Hymenoptera and also the seasonality of 53 species of butterflies (Lepidoptera; Rhopalocera). The relationship of insect abundance with the prevailing abiotic and biotic conditions has been examined. Three major sampling methods, namely sweep sampling, knockdown sampling and light trapping were used for the general insect sampling, while transect counting method was employed for the estimation of butterfly abundance. Other methods involving direct and indirect visual estimation of insect abundance employed in the field in an experimental basis for relatively shorter durations are also described.
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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.