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 Avian Responses to Varying Landscape Parameters in Mangrove Forests of Coastal Gujarat(Wildlife Institute of India, Dehradun, 2015) Kulkadia, Devanshi; Talukdar, G.; Gopi, G.V.; Sivakumar, K.Mangrove systems are the most productive ecosystems on the earth. The mangrove environment provides living space for dependent biota of more than two thousand species of flora and fauna of resident, semi-resident or migratory wildlife. The conversion of large contiguous tracts of the tropical mangrove forests to smaller patches embedded in a landscape matrix surrounded by human-altered habitats is one of the most serious concerns as it would affect their associated species such as birds, fishes, etc. In this context, this study was carried out aiming at discerning the responses shown by avifauna to varying landscape parameters like the mangrove patch characteristics, the level of disturbance and the structure of mangrove vegetation. Therefore, the abundance and diversity of the avifauna in mangrove forests at twenty selected sites on the coasts of Gujarat were investigated using point count surveys for a period of five months (December 2014-April2015). 2. A total of 98 points were laid across the twenty patches o(mangroves and surveyed twice during winter and summer seasons, respectively. Data were collected from the four replicates of each point during the entire study period. The total area surveyed during the study at these twenty mangrove patches was 47.97sq.km. These patches were ranging from various size classes with the smallest patch of the size of 0.125sq.km to the largest patch size was of 10.49 sq.km and were distributed throughout the coastline of 1650 km long. Habitat correlates such as structural and floristic characteristics of mangroves were quantified for each patch to establish their relationship with avifaunal abundances. 3. Despite recording only 7 species of mangroves in the twenty patches, a wide variety of birds totaling to 119 species were recorded from the mangroves during the two seasons, i.e. winter and summer during the study. 4. From the data collected by the variable-width point counts, the mean density of birds from the patches were calculated to be 6.485/ha in winter and 4.898/ha in summer. The diversity of birds varied across the seasons. A total of 104 species of birds were recorded during the summer season as compared to 117 species of birds in winter season. 5. Large contiguous patches of mangroves were found to be supporting fewer species of birds than the smaller patches. The avian species richness of the smaller fragments were largely governed by the adjoining environment settings (matrix) of the patch. Therefore, the study found that the diversity of the birds was not found to be getting influenced by the area of the patch as the species richness was found to be increasing with the number of the surrounding matrix. 6. It was found that the structural composition of mangroves especially the canopy cover was found influence the bird density and diversity greatly as with the increase in the canopy cover, the bird species diversity and density also increased in a patch. 7. The bird assemblages in the mangroves showed a significant response towards the disturbance. The disturbed patches contained an overlapping mixed composition of the forest birds and open country birds in an equal proportion, whereas the undisturbed patches showed less number of open country birds. 8. Based on the study, it is suggested that the larger sized mangroves patches are important for their ineffable ecological services, therefore, these patches should be protected and conserved. Similarly, the smaller and fragment of mangroves patches are also equally important as they hold a good number of avifauna! species and hence, we have to adopt some strategies to conserve all the remaining – large contiguous and small fragmented patches of the mangroves from further degradation.Item A Study of Resource Seletion by Black Kites (Milvus migrans) in the Urban Landscape of National Capital Region India(Wildlife Institute of India, Dehradun, 2013) Kumar, Nishant; Mohan, D.; Jhala, Y.V.Black Kites are the scavenger and predator raptors of the old world. In India they are synanthropic and perform the ecological role of city scavengers. Abundance and distribution of these birds suffers change due to rapid infrastructural changes in the developing cities which likely limit or change spatial layout of the available habitat and food. Many cities in the old world (London, Cape Verde, Istanbul) have experienced decline in the population of Milvus kites owing to rapid urbanization. Indian sub-continent almost lost its main scavenger, white backed vultures, in the last century. After this loss; existence of black kites, the most abundant raptor of the old world proves very vital. On these lines I carried carry out this dissertation from December 2012 to April 2013. This study focused on a) estimating the abundance of Black Kites on the Ghazipur dump site and the abundance of nesting pairs in National Capital Region (NCR), b) evaluating factors influencing nesting habitat selection combined with a broad understanding of its foraging habits and c) estimating nest survivorship in the urban landscape. I studied these parameters at selective study sites in NCR by intensive counts of birds at Ghazipur and breeding pairs at nest sites across eight study sites. Nests were searched intensively at each site while I tried to develop and test a new method to count the kites on the Ghazipur dump. Data from 116 nests and nest sites covariates were used to model nest survivorship under Known Fate scheme in Programme MARK. For my first objective, I estimated the current abundance of nesting pairs of Black Kites at 7 study sites. It ranged from 4 pairs / km2 in Sagarpur to 67 pairs / km2 in North Campus area. Nesting kites were selective while choosing a nest site, as evident by significant partial correlation between nest density, food index and green cover. The sites at the best trade-off between green cover and food availability had the highest nest densities. While developing a new methodology, I estimated around 2400 kites on the Ghazipur dump. Through behavioural observations and broad examination of regurgitated pellets, I could confirm scavenging as well as predacious nature of Black Kites. The overall probability of a nest to produce a viable fledgling was 0.45. The nest survivorship was stage specific and varied with pre-laying, incubation or nestling stage. The lower survival probability (0.60) at pre-laying stage is likely because of surplus nest formation at sites with good foraging opportunities. Understanding the importance of kites in urban ecology, studies using individually marked birds will reveal vital details of their behavioural and physiological adaptations. If future long term studies are conclusive enough, may establish Black Kites as an umbrella species of urban ecology.Item Occupancy Pattern and Food-Niche Partitioning Among Sympatric Kingfishers in Bhitarkanika Mangroves, Orissa(Wildlife Institute of India, Dehradun, 2011) Borah, Joli; Pandav, Bivash; Gopi, G.V.Eight species of kingfishers, Common, Collared, White-throated, Pied, Stork-billed, Black-capped, Brown-winged and Rudy, - coexist in the mangrove forests of Bhitarkanika along the east coast of India. Sympatric species with similar resource requirements need to have niche partitioning as a strategy to avoid competition in order to coexist together. To understand the mechanisms underlying such species coexistence, it is vital to know about the food requirements, foraging habitat preference, and how the resources are shared between these sympatric species. The present study attempted to understand the potential mechanisms that might play a role in food-niche differentiation and examined the occupancy patterns of four sympatric kingfishers i.e. Common, Collared, Black-capped and Brown-winged kingfisher in Bhitarkanika mangroves. I conducted field study from January to May, 2011 in Bhitarkanika mangroves. The creeks were catgorized as primary, secondary and tertiary creeks based on the branching pattern. A total of 16, one km trails were selected in the intensive study area. Each 1 km trail was further divided into 10, 100 m segments for Sub-sampling. During the survey only seven among the 10 segments of each 1 km trail were surveyed which were selected randomly with replacement. A total of 160 creek segments of 100 m length were surveyed for six times during the study period and relevant habitat variables were recorded. For foraging behaviour observation, point count method was used i.e., an individual bird was followed till it captured a prey and relevant foraging variables were recorded. A total of 53 independent prey captures were recorded for the four species of kingfishers. Focal animal sampling method was used and observations were made opportunistically for time budget observation. Detection histories were constructed for each segment for bird survey and all relevant covariates. The two model parameters i.e., the probability that a segment is occupied by the species ('I') and the detection probability (P) were estimated and analysed in the occupancy framework. For foraging behaviour and time budget analysis, different parametric and nonparametric tests were used. Occupancy analysis confined that Collared and Black-capped Kingfisher occur seasonally in Bhitarkanika mangroves; Collared being more abundant in summer and Black-capped in winter. For all the four sympatric species river/creek width had a negative association with detection probability. Habitat type also affected the detection probability of all the species except Collared Kingfisher. The detection probability of Common and Black-capped Kingfisher decreased with the increase in depth whereas it did not affect the detection probability of Collared and Brown-winged Kingfishers. Water current and turbidity were negatively associated with the occupancy of Common and Brown-winged Kingfisher. However for Collared and Black-capped Kingfisher, it differed with vegetation layer. Perch height and foraging distance differed significantly among the four species of kingfishers. All the prey characteristics i.e., prey type, prey size and foraging substrate differed significantly among the four species of kingfishers. This study reveals that each of the four species of kingfishers in Bhitarkanika mangroves occupy foraging niches corresponding to their respective body sizes. The occupancy pattern and foraging behaviour of the smallest species, i.e., Common Kingfisher and the largest species, i.e., Brown-winged Kingfisher is more similar. As, both mostly forage in water to catch fish, their occupancy is also determined by water current. They segregate in terms of prey size, which is reflected by the respective body sizes. On the other hand, the foraging behaviour of Collared and Blackcapped Kingfisher is similar in terms of prey characteristics.Item Behavioural Ecology of Colony Formation and Function of Colonial Breeding in Chtnut-Headed Bee-Eater.(Wildlife Institute of India, Dehradun, 2011) Supriya; Vasudevan, K.; Mohan, D.Breeding in densely distributed territories that contain no other resources apart from breeding site is known as colonial breeding. Despite several long-term investigations, there are several questions regarding colony formation, the function of coloniality and the variation in colony sizes that remain unanswered. Chestnut-headed bee-eaters (Merops leschenaulti) are tropical Old World birds (Family Meropidae) that breed both solitarily and in small colonies. Hence they are well-suited subjects for the study of colonial breeding. This study was conducted for five months from December 2010 to May 2011 in parts of Haliyal division and Karwar division in Uttara Kannada district, Karnataka. It is an attempt to explain the variation in colony size through gaining insights into the behaviour of colony formation and function of colonial breeding. A combination of measuring habitat characteristics, capturing and measuring birds, recording reproductive success of breeding pairs across a gradient of colony sizes and behavioural observations were used. A total of 17 nests were found during the course of the study distributed over three colonies and five solitary nests. No significant difference was found between habitat characteristics at solitary and colony nests. Also, there was no shortage of potential breeding sites, as found by the ratio of number of nests to the amount of substrate available. This suggests that the mechanism of colony formation in CHB is conspecific attraction and is not merely habitat mediated aggregation. The body size of the colony nesters was found to be greater than the body size of solitary nesters. This implies that the optimum colony-size is different for different individuals, with larger individuals having a preference for colony nesting. Program MARK was used to analyze nest survival data. It was found that the daily survival rate of nests was not significantly different across colonies of different sizes, lending further credence to the hypothesis that different individuals have different colony-size optima. Colony nests were initiated about a week before the solitary nests and nesting was more synchronous at colony sites. During the nest digging stage of breeding, a number of aerial chases were observed between the birds, which hint at a role for despotism in influencing variation in colony sizes. Provisioning frequency was found to be higher and showing larger variation at solitary nests than at colony nests. A possible explanation for this is that there is greater competition at colony sites. Therefore, colony-nesting must be having some other benefit that compensates for the cost of competition. Further investigations into the conspecific cue that mediates colony formation and· the benefit of coloniality need to be carried out.Item Responses Shown by Bird Communities to Teak Palatations in Sagar Forest Division, Karnataka(Wildlife Institute of India, Dehradun, 2009) Barve, Sahas S.; Mohan, D.; Qureshi, QamarThis study was aimed at discerning the responses shown by bird communities to teak plantations of various age classes in Sagar Forest Division, Karnataka within Latitude 13° 36' and 14° 38' North 74° Longitude 38' and 75° 32'East Latitude. Birds were sampled using line transects in three habitat strata, natural plantations, mature teak plantations and young teak plantations. Density, diversity and community similarity were the chief ecological responses that were quantified to bring out differences in the usage of forest plantations by native bird fauna. Habitat (vegetation) correlates, both structural and floristic were quantified to establish the reasons for differences. The sampling period was from December 2008 to April 2009. This period was divided into two seasons, winter and summer. A total of 9 transects were laid, marked and sampled at least 4 times per season. Birds were divided into three feeding guilds and three habitat guilds for analysis. The overall density of birds across the three strata was found to be higher in summer than in winter. However a guild level analysis showed that in winter while insectivorous birds were most abundant in natural forest with decreasing density towards young plantations (F (6.241) , p< 0.05). There was no difference in their density in summer. Phytophagous birds showed the exact reverse trend. Density of this guild was higher in young plantations than natural forests and mature plantations in winter and summer (F(S.689), p< 0.05), (F (14.302), p< 0.01) respectively. Overall diversity of birds showed a trend of decreasing species richness from natural forests to young plantations in both seasons. However this difference was almost non existent in summer at the guild level. The abundance of birds belonging to evergreen and moist deciduous forests shows a consistent· rise in abundance from winter to summer in all the three strata. There is also evidence that there is ingression of individuals of species that were common to both seasons possibly for nesting. The overall community similarity is quite high between the three strata and it increases from winter to summer. Bird diversity was found to be affected by the vertical spread of vegetation and tree height heterogeneity (R=0.871, pItem Resource Tracking by Three Species of Hornbills in Rajaji National Park, Uttarakhand, India(Wildlife Institute of India, Dehradun, 2009) Warrier, Rekha; Ramesh, K.; Rawat, G.S.Resource tracking is the ability of organisms to adjust to variations in resource availability through numerical or functional responses. Numerical responses may be manifested, by changes in demographic processes or, through changes in movement patterns. Altered space use patterns can result in abundance fluctuations from the local to the landscape levels. An in-depth knowledge, of how resource fluctuations affect patterns of space use and abundance of a species can augment the conservation efforts which are underway for many species. Through this study, responses of three species of hornbills viz, Great Hornbill (Buceros bicornis), Oriental Pied Hornbill (Antharcoceros albirostris) and Indian Grey Hornbill (Ocyceros birostris), to the spatio-temporal variation in fruit abundances were studied in Chilla Range of Rajaj National Park, India. The study was carried out between December 2008 and April 2009, using a grid based occupancy framework and systematic sampling procedure. A total of 28, 1 km grid cells (spatial replicates) were sampled on nine occasions (temporal replicates) for quantifying hornbill responses to fruit abundance patterns. Fluctuations in fruit abundances were assessed by means of phenology transects, which were monitored once every month. Ecological Niche Factor Analysis was done to index the fig fruit availability by modelling fig tree distribution with Eco-geographic variables. Hornbill responses to fruit availability were analysed at two spatial (habitat types and fruit patch level) and temporal scales (winter and summer). Of the three species targeted, data could be consistently obtained only for Oriental pied hornbills. Great hornbills were rarely encountered and Indian grey hornbills were seen commonly only towards the end of the study period. Thus the detailed analysis focused only on Oriental pied hornbills. During the study, non fig fruit availability showed severe variations across areas, and over time. The month of March seemed to be the period of absolute non-fig fruit resource shortage. Figs, especially Ficus rumphii, were the only species that fruited and helped sustain the frugivore community during this period of scarcity. Thus, Ficus rumphii is a potential key stone species for the area. The bias corrected occupancy estimates revealed that Oriental pied hornbills frequented the forest types (Miscellaneous forest) that had high fruit availability in both seasons. At the patch level, intensity of grid use was positively correlated with abundance of non fig fruits in winter (r = 0.5, pItem Winter Ecology of Three Species of Phylloscopus Warblers(Wildlife Institute of India, Dehradun, 2007) Ghosh, Mousumi; Singh, Pratap; Mohan, D.This study focused on three species of Phylloscopus warblers, P. humei, P. xanthoschistos, and P. chloronofus which overwinter sympatrically in the foothills of western Himalayas. The patterns of habitat occupancy, foraging behaviour, and foraging microhabitat of three species of warblers were examined to determine the nature of ecological complementarity facilitating their co-existence in the non-breeding season. Moreover, investigating the morphology-ecology associations among congeners also becomes critical since recent divergence may hinder our understanding of the mechanisms of their ecological segregation, as is the case with these species. Hence, morphology-ecology associations were also examined. A total of 91 points were sampled for bird detections five times each between December 2006 and March 2007. Prey abundances across habitat types were quantified. Behavioural data was also collected. The three species were found to differ in the occupancy of the sampled area. However, the bird occupancy did not correlate with differences in prey abundances across habitat types. The warbler species showed clear segregation in the use of foraging behaviour, foraging microhabitat, and proportion of large prey intake. The movement pattern was also found to vary across the three species. Morphology-ecology associations revealed the close interaction of morphology and ecology in shaping the ecological segregation of the three species in the non-breeding season. One major finding was that P. xanthoschistos is able to meet its demand for large arthropods in this northern site (31.5 % large prey intake) previously believed to be low in large arthropod abundance. Finally, the study demonstrated that the ecology of P. xanthoschistos (previously Seicercus) is very similar to other members of the genus Phylloscopus.Item Habitat Selection by Indian Peafowl (Pavo cristatus linn) in Gir forest, India(Wildlife Institute of India, Dehradun, 1993) Trivedi, Pranav; Johnsingh, A.J.T.A study on habitat selection by Indian peafowl (Pavo cristatus) was carried out in Gir National Park and Sanctuary over a period of five months. Open width line transects were laid at three study sites in West, Central and East Gir respectively to obtained information on availabili ty and use of habitats. Three hundred and thirty sightings were obtained in 90 transect walks (totalling to ca 113 km), of which two hundred and fifty occurred in West, and forty each in Central and East Gir. As sampling intensity was the highest in Sasan (West Gir), much of the analyses is based on the data collected here. Peafowl distribution was found to be clumped, with the degree and site of clumping being affected by water and food availabilityItem Avian Communities in the Riparian Areas of Bori Wildlife Sanctuary, India(Wildlife Institute of India, Dehradun, 1993) Pai, Ashwini; Johnsingh, A.J.T.Riparian areas are important as special habitats and corridors for wildlife. However, in India, riparian areas have not been studied to any detail. Also, not much is known about the avifauna of riparian habitats. The vegetation near a riparian area tends to be dense and hence distinct owing to constant availability of water. Riparian areas come under heavy use, both by livestock as well as wild animals because of the presence of water and forage. The avifauna of riparian areas is rich due to its floral complexity and structure and resources like fish and insects. This study quantified bird species diversity, avian guilds and avian community structure found in four riparian areas ( a flood plain, a riparian scrub, a disturbed nulla and an undisturbed nulla) of Bori sanctuary in Central India. The riparian areas were compared with the adjoining deciduous forest for avifaunal differences. Vegetation was studies along the riparian areas and the deciduous forests, using circular plots. Tree and shrub densities, vertical stratification of foliage and species richness were quantified. Line transects were used to estimate bird ,species richness and abundance. Bird species richness was correlated to negative variables for the two seasons. In summer the BSR was highly correlated with CC and in winters with CC. Stepwise multiple regression was used to create a habitat model for BSR in summer and in winter. Community patterns show seasonal change and also respond to structural changes of habitat.