Theses and Dissertations
Permanent URI for this communityhttp://192.168.202.180:4000/handle/123456789/1
Browse
5 results
Search Results
Item Study on Avian frugivory in Tropical Mixed Dry Deciduous and Scrub Forest in Southern India(SACON, 2012) Aruna, R.; Balasubramanian, P.Mutualistic plant-animal interactions exist in a wide variety with one of the most important being seed dispersal or the transport of seeds away from a parent plant by animals. Not only plants depend on animals for the dispersal of their seeds, animals, too, rely on plants for fruit as a food resource. Avian frugivores are considered the most important seed dispersers in several ecosystems, as assessed by the numbers of successful propagules disseminated. Fruit-eat in g birds play a critical role in the functioning of tropical ecosystems and may assist in the natural regeneration of forests by dispersing seeds into cleared areas. Seed dispersal by animals and frugivory have reached the pinnacle in tropical forests, where a percentage of up to 90% of tree and shrub species produce fleshy fruits adapted to animal dispers.:11 and eaten by a large number of vertebrates. In tropical forests, frugivorous animals are the dominant group of vertebrates. The challenge of frugivores is to find, eat and subsist partially or entirely on fruits that arc mostly deficient in protein, but rich in carbohydrates or lipids. Fruit availability is one crucial factor influencing the frugivore community. A study on frugivory by birds was carried out in two forest types namely, Tropical mixed dry deciduous forest in the Western Ghats and Scrub forest in the Eastern Ghats, Southern India. The research work was carried out in the tropical mixed dry deciduous forest of the Anaikatty hills of Nilgiri Biosphere ReserveItem Phyto-Ecology, Lion-Tailed Macaque, Macaca Silenus, Habitats, Southern India(SACON, 2002) Krishnamany, R; Kumar, AjithThe causal factors for the very high species diversity in tropical rainforests have been the focus of ecological research for several decades. It has become obvious that the high tropical species diversity has three major components, local (often called α-diversity), regional (β-diversity), and landscape (γ-diversity). Contribution of each of these components to overall diversity might vary from place to place, and from taxon to taxon. The pattern of variation in plant diversity is of particular interest since this would have a profound impact of the distribution and abundance of secondary consumers. In this study, I examine the nature and extent of spatial variation in the species diversity of woody plants in the rainforest of the Western Ghats Mountain ranges in south India, one among the eight most threatened biodiversity hotspots of the world. I also examine whether the diversity of food trees of the lion-tailed macaque (Macaca silenus), an endemic to the tropical rainforest of the Western Ghats and phylogenetically the ancestor of all extant Asian macaques, also show variation at different spatial scales that is similar to that of all wood plants. Since the phenology of plants also affects the secondary consumers, this issue is examined at one siteItem Floristic Composition and Patterns of Regeneration of Rainforest Trees in the Fragmented Forests of the Anamalai Hills, Southern Western Ghats(Wildlife Institute of India, Dehradun, 2003) Balasubramaniam, Priya; Qureshi, Qamar; Chellam, RaviThe word diverse is almost a synonym for tropical rainforests. In no other habitat are found such an enormous number of life forms. These highly diverse systems are now facing severe threats as a result of habitat fragmentation. The aim of this study was to study the floristic composition and patterns of regeneration in the fragmented forests of the Anamalai hills, southern Western Ghats.Six fragments were chosen which varied in size and disturbance levels. They were- Iyerpadi (>2600ha), Andiparai (>185ha), Puduthotam (92ha), Pannimedu (66ha), Varattuparai 1c (11ha) and Varattuparai 4 (4ha). Quadrats of · 3 sizes were used to sample for different variables. 20 x 20m quadrats were used to enumerate tree sp, 5 x 5m quadrats were used to enumerate sapling sp and 1 x 1 m quadrats were used to count the numbers of seedlings. Height (m), GBH (cm), lopping I cutting signs, altitude, canopy cover, presence of weedy shrubs and ground cover of weedy herbs were the other variables measured. A total of 112 quadrats were laid, 25 in the first 4 fragments, 9 and 3 in the last two respectively. The findings revealed that tree and sapling generic richness showed a negative relationship with disturbance and time since isolation. Their correlations with area though positive were weak. Fragments were subjected to varied nature and levels of disturbance. Fragment characteristics such as area, time since isolation did influence the patterns of tree and sapling composition though weakly. There is an extremely weak correspondence between the tree and sapling composition of each fragment. There was a high number ' of non rainforest species in fragments which were relatively more disturbed. Relatively undisturbed fragments were more rich in rainforest trees · and saplings. Fragments showing higher levels of canopy openness were relatively more disturbed than others. Disturbed fragments also showed higher levels of weed invasion. Iyerpadi showed the highest generic richness in trees and saplings. Varattuparai 4 showed the least richness in both trees and sapling. Human disturbance due to its chronic. nature was the principal predictor of both tree and sapling composition.Item Density Related Behaviour of Select Ungulate Species in Four Zoos of Southern India(Wildlife Institute of India, Dehradun, 2003) Panda, Prajna Paramita; Choudhury, B.C.Density Related Behaviour of Select Ungulate Species in Four Zoos of Southern IndiaItem Health and Sexual Signals of Male Asian Elephants (Elephas maximus) in Nagarahole National Park, Southern India(Wildlife Institute of India, Dehradun, 1999) Nath, Cheryl; Johnsingh, A.J.T.Male Asian elephants (Elephas maxim us) were studied at Nagarahole National Park, southern India from November 1998 to May 1999. Information was collected on at least 30 identified individuals for investigation of the possible use of musth and tusk length by males as signals of health and genetic fitness to female elephants. This study followed an earlier study by Watve and Sukumar (1997) which showed a significant negative correlation between tusk lengths and parasite loads in male elephants of the Mudumalai Wildlife Sanctuary, southern India. In this project, musth was studied in . addition to tusk length as a possible indicator of good health. It was hypothesised that musth and tusk length in male elephants would be related to better health and body condition and hence could potentially be considered as signals of better genetic quality, within the framework of Zahavi's theory of honest signaling (1975, 1977) and Hamilton and Zuk's theory of heritable true fitness (1982), respectively. The indicators of better health and body condition used were a subjectively scored body condition index (SCI) and a quantitative assessment of intestinal helminth parasite density (parasite load). Individuals were identified by a combination of several physical features, photographic records were obtained for height and tusk length measurement and information was collected on body condition, parasite loads, musth intensity and social interactions. The following interesting results were obtained: 1. Individuals exhibiting signs of early musth had significantly better body conditions and lower parasite loads than individuals exhibiting no signs of musth. 2. Longer tusks were not significantly correlated with better body condition, lower parasite loads or musth in this study.3. Dominance behaviours recorded in dyadic interactions among male elephants indicated that dominance was associated with musth, height of the animal and tusk length in a high percentage of interactions (100%, 89% and 78%, respectively).The significant association between early musth and better body condition as well as between early musth and reduced parasite loads indicates that male elephants may require better health in order to attain musth. Hence musth appears to be a potential honest signal of better than average health, in males which are able to attain this condition. This information may be used by female elephants in choosing mates. Social interactions among males corroborated this speculation by showing that musth and height in male elephants may be important determinants of dominance, which in tum may influence female choice and reproductive success. Limited samples of male-female interactions suggested that females discriminate between different males, and that male-male dominance interactions may influence female choice. However, small sample sizes limited the extent to which these findings could be extrapolated in this and other elephant populations.