PhD Theses (SACON)
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Item Breeding Ecology of the Edible-nest Swiftlet Aerodramus fuciphagus and the Glossy Swiftlet Collocalia esculenta in the Andaman Islands, India(SACON, 2009) Manchi Shirish, S.; Pramod, P.The intriguing biological feat of making nest with its saliva is threatening the survival of the edible-nest swiftlet. Ever since the16th century when bird’s nest became a delicacy in Chinese cuisine and an important item in their pharmacy, edible nest swiftlets are found overexploited all over. In the past two to three decades the production of the edible bird’s nests has reduced drastically because of overexploitation and uncontrolled harvesting that is directly affecting the population of this cave-dwelling species. The high demand in the international markets has put so much pressure that despite strict regulations on nest collection, the wild populations of the edible-nest swiftlets is plummeting by as much as 80% to 90% and has reached local extinction across some of their ranges. To understand the nest-site requirements of the species, their nest-site characters, preference and the relationship with nesting success were studied. Results showed that the edible-nest swiftlet and the glossy swiftlet are cave dwelling trogloxenes and do not nest randomly inside the cavesItem Status and Ecology of the Andaman Crake(SACON, 2009) Ezhilarasi, N.; Vijayan, LalithaAndaman Crake is a rare and endemic bird of Andaman Islands. There was no detailed information available on this species and was listed as data deficient till recently. Hence a study was undertaken during 2004-2007 to collect baseline data on the population, ecology and biology of the Andaman Crake. A variety of factors is responsible for Andaman Crake's habitat degradation and loss. In this chapter I briefly highlight key findings of this study, major threats to this species and suggestions for conservation and future research. While these threats and recommendations are given for the conservation of the Andaman Crake, they pertain to several other species ecologically dependent on the wet forests.Item Levels of organic contaminates and select biomarkers in the birds of Gujarat and Tamil Nadu, India(SACON, 2009) Dhananjayan, V.; Murlidharan, S.There has been an ongoing concern about the presence of different types of contaminants in the environment and their ill effects on wildlife, particularly birds. While substantial information is available on such in effects on birds elsewhere in the world , very limited data exist in India, A study was initiated to document the environmental residue levels of certain persistent organic contaminants, chemicals responsible for incidences of mortality of birds and, generate information on the levels of cholinesterase in brain and blood plasma of birds. The major objectives were to understand tissue specific accumulation of contaminants, namely organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs) and polycyclic a romatic hydrocarbons (PAHs) in birds, examine the variation in accumulation pattern between sexes and feeding habits, identify normal or reference levels of biomarkers, namely acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) to explain mortality of birds. Two representative cities, namely Ahmedabad, Gujarat in the west and Coimbatore, Tamil Nadu in the south were selected as study locationsItem Bird communities and their distribution pattern along the elevation gradient of Teesta Valley, Sikkim(SACON, 2008) Acharya, Bhoj Kumar; Vijayan, LalithaStudies on ecology of local communities are important for understanding environmental problems and planning area-based conservation management (Simberloff, 2004). Community composition, species richness and diversity of birds in five different elevation zones of Teesta valley, Sikkim were studied from June 2003 to March 2006 using point count sampling method. A total of 329 species of birds (299 during regular quantitative sampling and 30 during. opportunistic observations) belonging to 44 families was recorded in the Teesta valley during the study period. The study shows that Teesta valley harbors high diversity and abundance of birds. Broadleaved vegetation, situated at mid-elevation region, is the most diverse zone as compared to tropical, coniferous or alpine vegetation. Species accumulation curves based on number of point counts indicated that most of the species were detected in all the zones. Species richness (observed and estimated) was the maximum in zone II, whereas density, abundance and diversity were the maximum in zone iii. The species-abundance pattern of birds followed truncated log-normal distribution for total bird population as well as for all the zones except zone II which did not fit to any models. Bird data showed the presence of both types of species, exclusive (restricted to one elevation zone) and generalists (present in two or more zones), in the Teesta valley. Out of the total species observed (329), 156 (47.4%) were exclusively recorded in one specific elevation zone. Only three species, namely Blue Whistling Thrush, Greenish Warbler and White-capped Water Redstart occurred in all the five zones.Item Bird community structure along the altitudinal gradient in Silent Valley National Park, Western Ghats, India(SACON, 2008) Anoop Das, K.S.; Vijayan, LalithaMy research on bird community along the altitudinal-habitat gradients and their nest-site partitioning across habitats in Silent Valley National Park (SYNP) has portrayed several patterns. The work has explored some aspects of the processes which accounted for the patterns of variations in the community structure of birds in a pristine forest representative of the post Miocene and Pleistocene uplifted Western Ghats of India. In particular, the study addressed how altitude affected the distribution of birds and how the breeding birds shared their resources. The present study resulted in 5253 birds of 108 species, including 14 endemic species, from the 2314 point counts conducted in six habitats. The total number of species observed was 145 including opportunistic observations. Bird community structure of various habitats in corresponding altitudes varied significantly in terms of composition, abundance and diversity. The maximum species (59.2%) and individuals (27.2%) were in evergreen forest habitat and minimum in BLHF (22.8 % and 5.73% respectively). Shola habitats located at higher altitudes in the study area possessed higher species richness than mid-elevation broad leaved hill forest, which occurs within the altitudinal range of 1500- 1700 m. BLHF could be considered as a transitional zone between evergreen and shola forest. The significant difference in tree species richness of BLHF with adjacent EG and SHOLA habitats partly explain the reduction in number of bird species in this transitional zone.Item Status, distribution and ecology of the Grey-Headed Bulbul Pycnonotus Priocephalus in the Western Ghats, India(SACON, 2007) Balakrishnan, P.; Vijayan, V.S.The Western Ghats of peninsular India is one of the globally important ecoregions harbouring some of the fine rainforests of the world. This mountain ranges host more than 507 species of birds including several endemics little is known, however about the ecology and conservation status of many species. Habitat loss and fragmentation due to human activities the major threats to the restricted-range birds of the Western Ghats. Their narrow habitat requirements, particularly during the breeding season are yet another possible important factor causing their decline. Hence, evaluation of their basic ecological requirements, particularly their selectivity to microhabitats during breeding is of significant value while formulating conservation programme for these species. The Grey-headed Bulbul is a poorly known endemic to the Western Ghats. This restricted range species has a very limited distribution in the heavy rainfall areas in the hills along the south-western side of India from Belgaum and Goa to Kanyakumari. Observations, including both sightings and collections of Grey-headed Bulbul are very few from 1869 to 2002. It W3S reported as '"fairly common but rather local". However, the recent surveys do not show 'common' in any of the areas covered. This indicates a decline in population probably due to habitat loss and fragmentation. In the above background a detailed study was carried out to assess the status and distribution of Grey-headed Bulbul in the Western Ghats with respect to altitude and habitat and, to explore the habitat selection, for3ging ecology and breeding biology of the species to identify key factors affecting its long- term conservation. Intensive field surveys were Carried out between February 2002 and January 2004Item Status and Ecology of the Nilgiri Pipit in the Western Ghats.(SACON, 2007) Vinod, Uma J.; Vijayan, LalithaStudy was undertaken on the Nilgiri Pipit with the following main objectives a) determine the status b) unravel the ecology c) identify the key factors affecting the survival of the Nilgiri Pipit and suggest management optionsItem Status and ecology of the Nilgiri Wood Pigeon in the Western Ghats(SACON, 2006) Soumasunderam, S.; Vijayan, LalithaConservation of the species requires a comprehensive picture on the status and distribution, ecological requirements for feeding, breeding and other activities. Ecological studies on most of the endemics have not yet been conducted and hence, such information is not available for any management programmes. Moreover, human impacts on the habitats of most species are also not understood. Hence, the present study was conducted on an endemic, endangered species of the Western Ghats which is considered as Globally Threatened, the Nilgiri Wood Pigeon Columba elphinstonii, addressing mainly its biological and ecological requirements.Item Habitat utilization by Malabar Grey Hornbill at Mudumalai Wildlife Sanctuary, Western Ghats. (TH12)(SACON, 2002) Maheswaran, B.; Balasubramanian, P.Utilization of habitat resources, particularly fruit and nest trees, by an endemic bird species, Malabar Grey Hornbill (Ocyceros griseus) was studied in a tropical semi-evergreen forest and the adjoining tea/coffee plantations at Mudumalai Wildlife Sanctuary, Western Ghats. This bird species is mainly distributed in the moist forests of southern Western Ghats. Though some aspects of Malabar Grey Hornbill in an evergreen forest at Anamalai Hills have been studied during the breeding season, fruit utilization during the non-breeding season is not known. Also, the preference of this endemic hornbill for food and nest tree species is unknown. This study aimed to assess the food preferences of Malabar Grey Hornbill during breeding and non-breeding seasons, nest-tree preferences and to identify the keystone resources for the Malabar Grey Hornbill in the semi-evergreen forest.