M Sc Dissertation(WII)
Permanent URI for this collectionhttp://192.168.202.180:4000/handle/123456789/3
Browse
4 results
Search Results
Item Space Use Patterns of the Indian Giant Squirrel (Ratufa indica centralis Erxleben) in Relation to Food Availability in Bori Wildlife Sanctuary, M.P. India(Wildlife Institute of India, Dehradun, 1993) Datta, Aparajita; Goyal, S.P.The spatio-temporal heterogeneity of food supply and the consequent effects on food resource use and space-use patterns of the Indian giant squirrel (Ratufa indica centralis) in Bori Wildlife Sanctuary, was the focus of study. Territoriality, which may affect space-use patterns of individuals was of special interest. Climatic factors which may influence activity budgets and consequently the variability in seasonal space-use patterns are also discussed. Based on individual variation in physical characteristics, Z identified three focal animals (one male, one female and a subadult male) in the disturbed habitat (Bhainsa nala ) , and a male and female in the undisturbed habitat (Churnagundi nala) for whom dana could only be gathered in winter. Therefore seasonal changes in space-use patterns is discussed for focal squirrels in the disturbed habitat. I kept a continuous record of behaviours during focal animal sampling. Home areas were calculated based on hourly locations taken from focal data. I gridded the area used by focal squirrels and recorded the vegetation parameters. The seasonal change in resource availability was monitored by phonological observations on all trees in the grids twice a month. Squirrels in Bhainsa nala selectively utilised certain individuals of flowering and fruiting crees which was related to crop size. Squirrels included bark and leaves in their diet even when fruit resources were available. The resource use by squirrels in Churnagundi nala showed a marked difference from squirrels in Bhainsa nala in winter which was due to the poor availability of food. Individual squirrels in Bhainsa nala showed variation in food species, food items used and the percent time spent feeding on each food item indicating that resource availability was not the same for all squirrels. No significant correlation was found between resource abundance and percent use of the item. Squirrels had overlapping ranges but were otherwise solitary. Many preferred resources were rare in the habitat, and the spatio-temporal heterogeneity in food resources resulted in overlap between individuals at locally abundant food resources. Because of this heterogeneity, the defence of an exclusive area guaranteed of resources throughout the seasons is not possible. Therefore squirrel ranges overlapped, but encounters were avoided by spatial time sharing but when encounters occurred, overt aggression was seen. But at certain locally abundant resources which were located at the periphery of the home areas, squirrels tolerated each other by maintaining inter-individual distances (5-10m). The tolerance of conspecifics at these resources could also be related to the existence of dominance hierarchies which result in decreased over aggression. The intensity of use (time spent) decreased as the distance from nest increased for all squirrels. Squirrels made forays in search of food and in many cases foraging was in the peripheral areas of the range. The male’s range showed overlap with the female’s in winter which could be related to sexual activity. Squirrels had a bimodal activity pattern in both seasons but bimodality was less pronounced in the winter since activity was distributed throughout the day when temperatures were more equable Shift in onset and cessation of activity was observed with changing daylength. Time spent feeding in April was much less than in other months. Time budgets showed that in all months a higher proportion of time is spent resting which could be due to heat or cold stress in or time needed to digest food items eaten. in Activity pattern of the squirrels in winter in Churnagundir nala were influenced by the low resource availability which resulted in long basking and resting periods and negligible time spent in feeding. Though occasional forays of short duration were made, no food was located by these forays. Thus squirrels adopted a strategy of conserving energy by minimizing their requirements by resting.Item Food habits and foraging behaviour of Indian Gazelle (Gazella benneti) in Rajasthan desert(Wildlife Institute of India, Dehradun, 1997) Kodoth, Ganesh; Goyal, S.P.The Indian gazelle inhabiting the arid regions is studied with respect to their food habits and foraging behaviour. In arid areas the selection of a habitat by an animal is mostly governed by spatial and temporal distribution and abundance of food items and the food requirements of that species. This becomes critical especially in an semi-agricultural landscape where the ecosystem is altered without any consideration for the animal. The study was conducted in a habitat close to human habitation around Jodhpur after the harvest. This area is dominated by desert vegetation such as Crotalaria burhia. The study is conducted for a period of six months encompassing two seasons winter (December 15, 1996 - February 20, 1997) and summer (March 20, 1997 - May 10, 1997). The intensive study area was differentiated into six habitat types based on the structural and floristic composition of the vegetation-viz, crop fields, fallow lands, scrub area dominated by Zizyphus, and hedges of Maytenus-Capparis Zizyphus among the agricultural fields. Differential habitat selection by gazelle was observed during summer and winter mainly due to selection of diet based on seasonal nutritional requirements. Diet selection is looked in terms of use-availability and plant chemistry. Based on a relative preference ratio, the habitat and food types were ranked, and the observed trends are explained in terms of the existing theories on diet selection. Diet composition varies with the age and sex classes of the animal viz. breeding males, sub-adult males and adult females. In winter and summer differences in habitat use was exhibited by gazelle, also there was a difference in proportion of the food species in the diet between two seasons. The scrub area was dominated by vegetation having higher crude protein and tannin, was used more than, available in order to supplement their diet (especially in the case of , females) and in summer the crop fields dominated by Crotelaria burhia were used more by all categories of animals. Females fed on a high protein and less tannin diets which is pronounced in winter, sub-adults also fed on a diet having higher protein and tannin, while males were not biased towards a high quality food both in winter and summer. These differences were influenced by the spatial distribution, of food species, plant chemistry, and the differential use of food species among different age and sex classes during the two seasons. Protein and tannins along with moisture seem to govern diet selection rather than just being a function of availability during winter and summer. Spatial distribution of food plants along the habitat types (in the current land-use pattern) does influence habitat use by gazelle. Selection and proportion of the time spent on food species during summer and winter suggest that Indian gazelle is a browser.Item Utilisation of Major Fodder Tree Species with Respect to the Food Habits of Domestic Buffaloes in Rajaji National Park, India(Wildlife Institute of India, Dehradun, 1995) Edgaonkar, Advait; Goyal, S.P.The fodder tree utilisation patterns of the domestic buffaloes of the Guijars. a transhumant pastoralist community in Rajaji National Park were studied from November 1994 to April 1995. The study was conducted in three forest .blocks in Dholkhand range with different levels of lopping. Thirty three tree species were used as fodder, of which 11 were important. Milletia extensa, Miliusa velutina. Anogeissus lotifolia, and Grewia elastica were some of them. I calculated a preference index for these II major fodder trees using utilisation and availability data with a confidence interval. Ten out of II species were neither significantly preferred nor avoided in winter, Shoreo robusta being significantly less preferred. In spring. Milletia extensa was 'less preferred out of the five utilised; the others were neither preferred nor avoided. A feeding trial was conducted for seven species in which Stereospermum suaveolens was significantly preferred and Terminalia beleriea was significantly avoided. Neither utilisation nor preference correlated significantly with percentage N. Ca., Ash and Crude Fibre. Lopping of most trees was done regardless of the phenophase as long as the species had foliage. The Guijars faced a seasonal scarcity of fodder in spring. [t is argued that preferences break down in a situation of scarcity and any species edible to the buffaloes is lopped. Even a clearly less preferred species like sal is used. A comparison between occurrences of seedlings of buffalo fodder and nonfodder species between a lopped and a negligibly lopped block showed significant differences. The lopped block had more seedlings. An index of dietary similarity between domestic buffaloes and elephants gave an overlap of 39 percent.Item Food Resource Partitioning Among Sympatric Bovids Chinkara, Blackbuck and Nilgai in Rajasthan Desert(Wildlife Institute of India, Dehradun, 1989) Kunhunu, N.V.Ashraf; Goyal, S.P.Patterns of dietary selection, overlap and spatial distribution were investigated for three species of sympatric wild ungulates and four species of domestic ungulates (goat, sheep, camel and cattle> during four seasons (summer, pre monsoon, monsoon & post monsoon) in Rajasthan desert. The objective was to determine the mechanisms of food resource partitioning among these seven species of ungulates and the factors allowing their coexistence. Two study areas, Dhawa-Doli and Janwar-Doli were selected for the study, based on the density and distribution of the three wild ungulates. More emphasis was given to Dhawa-Doli where two of the three species (chinkara & blackbuck> were common. Food habits were studied by direct observations. Feeding activity was recorded for feeding height, plant species and part eaten. Availability was determined by percentage cover classes. Three major vegetation zones were identified at Dhawa-Doli. Six study sites were selected across the three vegetation zones. Blackbuck were primarily grazers in monsoon when crops were beginning to grow and annual plants were abundant. Chinkara and nilgai browsed throughout the study and did not show any preference for monocots in periods of resource abundance (monsoon and post monsoon). Food habits of wild ungulates differed more between zones in summer and pre monsoon, when resources were limiting and the effect of vegetation zonation on food habits was evident. In monsoon and post monsoon when resources were abundant, the effect of vegetation zonation was negligible as opportunity for selection increased. Though dietary similarity was more in terms of plant species eaten between chinkara and goats and between sheep and blackbuck, they differed greatly in proportion of utilization. Greater overlap between chinkara and blackbuck during premonsoon suggest a possible temporary interspeciflc competition. In scrublands, dietary overlap was more between species with similar feeding strateg1es (goat & chinkara - sheep & blackbuck) and was less between species with dissimilar feeding strategies. Nilgai was spatially separated in summer and pre monsoon and showed a seasonal spatial overlap w1th chinkara and blackbuck at Dhawa-Doli during crop season. While blackbuck and nilgai exhibited a spatial divergence in response to temporal and spatial availab1lity of food resources, chinkara was largely sedentary. Though utilization of different habitat subun1ts (crop fields, cultivated fields and scrublands) were largely determined by the amount of disturbance, ch1nkara showed a random utilization of these subunits. Blackbuck showed a slight avoidance for crop fields, at least at day time, even though they consumed more crops than chinkara. Mean feeding height for domestic ungulates decreased towards post monsoon as they spent more time feeding on annuals. However, the mean feeding height for wild ungulates increased in response to the growth form of plants. The difference in utilization of different foraging strata was more evident between browsers and more similar between grazers. Broadly, this study suggests that dietary differences among all species were more important than spatial differences, in food resource partitioning.