M Sc Dissertation(WII)

Permanent URI for this collectionhttp://192.168.202.180:4000/handle/123456789/3

Browse

Subject: search.filters.subject.mammals

Search Results

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Riverine Habitats Under Changing Land-use : A Resource Selection Study of Smooth-Coated Otter (Lutrogale perspicillata Geoffroy Saint-Hilaire 1826) in Kabini River and Tributaries
    (Wildlife Institute of India, Dehradun, 2015) Aneesh, C.R.; Hussain, S.A.; Johnson, J.A.; Talukdar, G.
    Habitat selection is an important part of the ecology of semi-aquatic mammals since they are highly specialized animals. River otters are especially vulnerable animals in the present situation due to increasing human disturbance, altering riparian vegetation damming and channelization in river basins. This study looked at the effect of land-use pattern on the habitat selection by otters with special reference to smooth-coated otter (Lutrogale perspicillata) in Kabini river, South India. The study showed fewer presence sites of smooth-coated otter inside the protected areas, due to naturally unsuitable habitats for the species, with shallower stream habitats in hilly terrains. These sites were occupied by Asian small-clawed otters (Aonyx cinerea). However the sign intensity was more in presence locations inside protected area and least in urbanized area. The detailed study in presence only sites revealed that anthropogenic disturbance primarily increasing human presence, fishing and grazing is the most important factor affecting selection of habitat by smooth-coated otter. The intensity of usage of habitat is also governed by disturbance factors. Other environmental factors are only secondary to disturbance factors affecting habitat selection which includes a set of factors pertaining to land and water summarized as slow, deep waters with intact bank cover and/or grassy banks with close escape cover distance. Prey fish species of medium size class (21-40cm) affects the habitat selection. Although Asian small-clawed otter and smooth-coated otter occur in same river system , there is a clear niche partitioning between these two species. The study also Looked at the effect of dams on otters which is the primary factor negatively affecting otter habitats. Yet flow regimes are mostly compensated due to more streams joining the main river channel. Increasing degree of habitat disturbance in different land-uses seems to negatively influence the fluvial functionality which is positively associated with otter habitat. The combined effect of isolation due to reservoir and increasing disturbances in downstream area pushes smooth-coated otters to select habitats upstream that are marginal to them and more suitable for small-clawed otters.
  • No Thumbnail Available
    Item
    Distribution and movement patterns of the Himalayan Black Bear (Selenarctos thibetanus Cuvier) in Dachigam National Park, Kashmir
    (Wildlife Institute of India, Dehradun, 1989) Saberwal, Vasant; Johnsingh, A.J.T.
    This study investigates the distribution patterns of the Himalayan Black Bear (Selenarctos thibetanus) in Dachigam Rational Park, Kashmir. It involved basically two components. (i) looking at the differential usage of different parts of the park by bears over a five month study period. and (ii) the spatio-temporal variation in the distribution and availability of fruit during the study. Dachigam National Park of 141 sq. km ranges in altitude from l800m to 4400m. It is divided into Lower (2& sq km) and Upper (115 sq km) Dachigam. Lower Dachigam (LO) is characterized by a broad valley flanked by steep hillsides. Upper Dchigam (UO) is composed of several gullies separated by fairly steep ridges. The valley vegetation is broad leaved, moist deciduous forest with an unusually high abundance pf fruit species. The slopes on either side are dominated by grass (south facing slopes) or a combination of grass, conifers and shrubs (north facing slopes). The vegetation of Upper Dachigam is mainly composed of coniferous species, with alpine meadows in the higher areas. Transects were walked through Lower Dachigam, considered to have over 90% of the Black Bear population of the park. to record animal locations and signs. especially droppings. 100m segments were marked along these transects and sightings and signs plotted accordingly. These segments were the basis of the habitat mapping exercise. A subjective estimate of the abundance of key fruit species was made for each segment. A phenology study looked at the timing of fruiting of key species. Data analysis shows a good, though not significant correlation between sighting frequencies and fruit availability. However there is strong suggestive evidence to indicate that anilla1 movements are largely Controlled by the spatial distribution and phenological status of five to six key fruit species. The lack of significance is probably due to the small data set. The study indicated the lack of defended territories. Instead, as reported from studies on the American Black Bear (Ursus americanus), there are marked seasonal shifts in the use of the home range. Feeding aggregations of up to 20 bears in one hectare are common. Densities of over 1.5 bears per sq km were recorded in Lower Dachigam at times of high fruit abundance. For two months of the year, May and August, black bears disperse out of the park due to very low food availability. Crop raiding (apple, cherry, and maize) is common at this time. The unusually high abundance levels of fruit in Lower Dachigam (due to oak, walnut, and mulberry plantations, over 70 years old) supports a high density of bears at certain times of the year. However, the lack of sufficient fruit at other times of the year is resulting in increasing levels of conflict with the local human population. Problems of oak and walnut regeneration, and the implications of extremely localized oak distribution are discussed. A more detailed study investigating the problem is suggested.