Abstract:Habitat degradation affects mixed-species bird flocks (flock hereafter) through two mechanisms – changes in the bird community from which flocks are drawn and changes in the propensities of species to flock. We determined the relative influence of these two mechanisms by examining variation in flocks across nine rain-forest fragments (range 11–2600 ha) in a plantation landscape in the Western Ghats, India. We found differences between fragments in average number of species (range 10.8–15.2) and individuals (range 19.0–37.6) per flock, number of species that participated in flocks (range 34–59), encounter rates (range 0.5–2.4 flocks h−1) and flock composition. Multiple regression and randomization tests revealed that different mechanisms contributed to this variation. Three flock variables (open-forest individuals per flock, total open-forest species that participated in flocks in a fragment, flock composition) mainly reflected changes in the bird communities of fragments. Habitat structure strongly influenced three flock variables (open-forest species per flock, total and rain-forest individuals per flock) and flock composition to a lesser extent. Finally, flock encounter rate was strongly related to fragment area, but not to abundance of flock participants indicating habitat degradation-induced changes in propensities of species to flock.

). Tigers fed on seven prey species as shown by kill data. Tigers' scat analysis revealed the presence of five prey species. Prey selection by tigers based on scat analysis was in the following order: sambar> chital> nilgai> livestock> common langur. It is proposed to restock the tiger population initially with five tigers in Sariska and subsequent supplementation of two tigers every three years for a period of six years, which will allow the population to achieve demographic viability. Removal of anthropogenic pressure from the national park will be crucial for the long term survival of tigers in Sariska.

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On Mundanthurai Plateau, from January to July 1984, chital (Axis axis) fed on 162 plant species. Contribution of various plant types (trees, shrubs, creeper/climber, herbs and grass) to the diet of chital varied from month to month. Grass group (ten species) had the preference rating of 10.14. Sambar (cervus unicolor) used 139 food plants. Sambar also showed monthly variation in its diet. Grass group had the preference rating of 9.92. Domestic cattle (Bos Indiens) used 90 food plants. Grass had the highest preference rating of 41.37.Dietary overlap between chital and sambar was 73 %, chital and cattle 65 % and sambar and cattle 49%. Elimination of cattle from Mundanthurai Plateau and creation of more grass patches would make more grass available to chital ultimately leading to an increase in its population. Resume. -Sur le plateau de Mundanthurai, de Janvier ä juillet 1984, le chital (Axis axis) se nourrit de 162 especes de plantes : 51 arbres, 23 arbustes, 29 lianes et 59 herbacees. La proportion des differents types de plantes (arbres, arbustes, lianes, herbacees et graminees) dans le regime alimentaire du chital varie de mois en mois. Les graminees (10 especes) sont preferees et represented 10,14% et Ageratum conyzoides 7,97%. Le sambar (Cervus unicolor) utilise 139 especes de plantes : 44 arbres, 23 arbustes, 28 lianes et 44 herbacees. II montre egalement une variation mensuelle de son regime. Les graminees ont sa preference, atteignant 9,92%, et Ageratum conyzoides 5,46%. Le betail domestique (Bos indicus) utilise 90 especes : 15 arbres, 15 arbustes, 13 lianes et 47 herbacees. Les graminees ont la preference la plus elevee : 41,37%. La superposition des regimes du chital et du sambar a etc de 73 %, celle du chital et du betail de 65%, et celle du sambar et du betail 49%. L'elimination du betail de ce plateau et la creation de plus de surfaces de graminees favorisera Taccroissement des populations du chital.

Prey depletion is a major (but often neglected) factor driving the current decline of tigers (Panthera tigris L.) (Karanth & Stith 1999). Thus conservation planning for the tiger in a fragmented, human-dominated landscape requires reliable information on prey densities from various parts of its range. We report numerical and biomass density of six herbivores from the tropical dry-deciduous forests of Ranthambhore Tiger Reserve (RTR, 26°N and 76°E), Rajasthan, India, where these are important prey for tigers (Bagchi et al. 2003).