Theses and Dissertations
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Item Open to Invasion Patterns in Fruiting Phenology and Seed Dispersal of Lantana Camara Across Different Habitats in North India(Wildlife Institute of India, Dehradun, 2021) Taneja, Yukti; Page, Navendu, V.; Kumar, R.SureshLantana camara (hereafter, Lantana) is a fleshy-fruited alien invasive plant that spreads mainly through seed dispersal mediated by vertebrate frugivores. Lantana has low shade tolerance and is thus more abundant in relatively open habitats. While open habitats may facilitate better germination of seeds and growth of saplings and adults, the role of habitat type on its reproductive output (fruits) and seed dispersal remains largely unknown. Understanding this can help predict differential patterns of invasion in different habitats. In this study, I aimed to understand the influence of canopy cover and other drivers on fruiting phenology, visitation patterns of frugivores on Lantana and fruit removal of Lantana. I carried out this study in Shorea robusta- dominated. moist deciduous forest and grassland-shrubland mosaics in and around the Wildlife Institute of India (WII) campus in the Dehradun valley, Uttarakhand from August 2021 to December 2021. To determine the influence of canopy cover on fruiting phenology, I marked and monitored (every fortnight) 45 Lantana bushes across a gradient of canopy cover from late August. To determine the drivers of visitation patterns of frugivores on Lantana and the fruit removal rates of Lantana across habitats, I earned out focal plant watch on 80 Lantana bushes across a gradient of canopy cover. I used a generalized linear mixed model (GLMM) to test the effect of canopy cover and shrub volume on the fruit crop size of Lantana bushes monitored for phenology.Item Study on avian frugivory and seed dispersal in the shoal forests of Nilgiri Hills, Western Ghats, India.(SACON, 2013) Anbarasu, C.; Balasubramanian, P.A study on avian frugivory and seed dispersal in 111'0 shola forests of Nilgiri hills, Western Ghats was carried out from January 2009 to July 20 I I. Longwood shola is situated between 11 °43.494'N and 0760 87A63'E) and Eppanadu shola between I lo29. IS]'N and 0760 47.223'E. The objectives or the present study were, i). study avian frugivory and find out major frugivores in the shola forests ii). assessing fruiting phenology of fleshy-fruited tree species and find out the fruiting seasonality, iii). establish the role of avian frugivores in seed dispersal and forest regeneration. Vegetation sampling was done in both the shola forests, Longwood and Eppanadu. One h3 plot (50x20m) were laid in e3ch of the above-mentioned two shola s. Data collected were analyzed to obtain quantitative structure and composition of plant communities. Fruiting periodicity was determined by monitoring tagged trees for 24 months.Item Studies on Frugivory and Seed Dispersal by Indian Grey Hornbill (Ocyceros birostris) in Sathyamangalam Forest Division, Eastern Ghats(SACON, 2010) Santhosh Kumar, E.; Balasubramanian, P.Seed dispersal refers the removal and deposition of seeds away from parent plants, by which a plant scatter its offspring away from their source of origin to reduce competition. Seed dispersal and its establishment are the crucial moments in the life cycle of plants which determine the success of plant populations. Basic knowledge about fruit-frugivore interactions and especially the seed dispersal process in forest ecosystems is essential for conservation of endangered animals and the forest itself. Fruit consumption by birds is an important species interaction that contributes to seed dispersal in forests. Hornbills, being primary frugivores of the tropical forest, play an important role in seed dispersal and regeneration of forest trees. Their ability to open and swallow large, ripe fruits and their defecation and regurgitation of undamaged viable seeds make them ideal dispersers. Hornbills are one of the most recognizable groups among birds. They are distributed in Sub-saharan Africa, Australia, South-east Asia and India. Among the 54 species of hornbills in the world, 9 species occur in India. Indian Grey Hornbill (Ocyceros birostris) also known as Common Grey Hornbill is distributed in India, Pakistan, Nepal and North-west Bangladesh. Hornbills have specific food preferences and foraging techniques. A review of literature revealed the absence of detailed research on Indian Grey Hornbill. Hence, a study was undertaken with the following objectives, I. assess 94 frugivory by Indian Grey Hornbill and establish its role in seed dispersal and regeneration of its food plants. The study was carried out in Sathyamangalam Forest DivisionItem Intra-specific variation in seed dispersal effectiveness of Lion-tailed Macaques Macaca silenus(Wildlife Institute of India, Dehradun, 2024) Bindu, K.; Kumar, H.N. Dr. H. N. Kumara Dr. Navendu Page Dr. Rohit Naniwadekar; Page, Navendu V.; Naniwadekar, Rohit1. Tropical forests are one of the most biodiverse ecosystems on Earth. Seed dispersal is one of the important interactions that maintains species richness and ecosystem functions. Vertebrate frugivores, especially birds and mammals, play a crucial role in dispersing seeds. The dispersal effectiveness of these dispersers is influenced by factors such as size, age, sex, dominance hierarchy and behaviour types. Invasive species pose significant threats to tropical ecosystems, rapidly forming mutualistic relations with native dispersers. This study focuses on the lion-tailed macaques Macaca silenus in the Western Ghats to explore how age-sex categories influence seed dispersal of native and exotic species in terms of diversity and quantity of fruits consumed, quantity of seeds dispersed, daily distance travelled and seed deposition site. 2. I employed non-invasive behavioural sampling on four troops of the lion-tailed macaques for four months. Focal animal sampling of 375.9 hours was employed on individuals belonging to three age sex categories, including adult males, adult females and subadults. Faecal samples were collected to assess quantity of seeds dispersed, and the substrate at seed deposition site was recorded. The movement of focal individual was tracked for the entire duration of the observation. 3. Subadults consumed higher diversity of fruits than females and males. Subadults also consumed more native fruits, while females consumed more non-native fruits. The pairwise dietary overlap between all age-sex categories was high. The rate of consumption of nonnative fruits increased as day progressed. Subadults dispersed significantly less Ficus seeds than the other age-sex categories. Daily movements showed no significant differences across age-sex categories. However, I found weak evidence of males being more likely to disperse seeds on trees, which could be more suitable for Ficus germination. The differences in 7 feeding patterns also highlight the greater importance of subadults in the dispersal of a greater diversity of fruit plant species. 4. The invasives Coffea spp. and Lantana camara constituted up to 90% of the diet of the three age-sex categories. There was difference in the relative proportions of these two species. Males consumed more Coffea spp., whereas subadults and females consumed more Lantana fruits. The macaques dispersed Ficus seeds in clumps, increasing the risk of predation or microbial infection. 5. This study generates novel information on intra-specific variation in seed dispersal, a relatively understudied topic. It also highlights lion-tailed macaques' significant role in dispersing alien invasive species in degraded rainforests and provides valuable insights into their understudied role as seed dispersers.Item Fruit Removal, Seed Dispersal and Demography of Emblica officinalis at Rajaji National Park, Uttaranchal(Wildlife Institute of India, Dehradun, 2001) Prasad, Soumya; Chellam, Ravi; Krishnamurthy, JagdishPlant-frugivore interactions determine the structure and composition of plant and frugivore communities and consequently the understanding of these interactions may help in defining the management protocol for the conservation of these systems (Howe 1993). E.officinalis fruit are an important non-timber forest produce from Indian deciduous forests. In this study I have looked at fruit removal and seed dispersal patterns of E. officinalis in the context of its use by humans. Fruit removal patterns were followed for 19 E. officinalis trees with a range of fruit crops (from 73 ± 59 X 103 fruit to less than 100 fruit) at Dhaulkand, Rajaji NP. 11 of these trees were monitored to ensure that there was no human removal of the fruit. For each tree, all fruit on the ground in the fruit fall area and all fruit on 5 -7 marked branches were counted thrice every ten days in 12-hour intervals, till less than 5% of the initial number of fruits remained on the .marked branches, to arrive at nocturnal and diurnal removal patterns for fruit. Factors affecting fruit persistence (number of days fruit persisted. on the marked branches) were extraction of fruit by people and fruit crop size. In the fruit-fall area, factors affecting nocturnal and diurnal fruit removal rates were clustering of fruiting trees and human induced factors. A range of direct and indirect methods - tree watches, track plots and camera trapping were used to determine the identity of the fruit removers and to observe the mode of fruit handling by these removers. Langur (Semnopithecus entellus), ungulates such as chital (Axis axis) and barking deer (Muntiacus muntjac) were observed feeding on E. officinalis fruit. There was also evidence that the gerbil, Tatera indica, scatter hoards the fruit. Retention In ungulate rumens reduced germination success of E. officinalis seeds. Demography of E. officinalis and regeneration status of woody plant species at Rajaji was assessed along 6 one Ian transects' across a gradient of human use intensity, 3 each in hill and plain mixed forests. The E. officinalis population at Rajaji was found to have very few trees below 30 cm GBH. E. officinalis seedlings were found only in areas almost completely free from human use. Regeneration for tree species at Rajaji was dominated by species that are not lopped for fodder.