India is rich in biodiversity and in high degree of endemism. Indian subcontinent is one of the 12 mega-biodiversity centres of the world and comprises two unique species rich areas viz., the Eastern Himalayas (part of Indo-Burma ‘Hot spot') and the Western Ghats (part of tropical forest). The Western Ghats hill ranges, recognised as one of the unique and distinctive biogeographic regions of the world is one among the hottest hotspots of biodiversity with a repository of biological wealth in terms of flora and fauna. Biodiversity hotspots are recognised on the basis of extent of endemism in plants, vertebrates, their density per 100 sq.km and remaining primary vegetation as percent of original extent in the region (Myers et al , 2000). Such regions always have high priority for conservation, primarily for the diversity and the ecosystem goods and services they provide. Excessive use of natural resources, environmental pollution and anthropogenic activities leading to the destruction of habitats, in recent years, are responsible for the loss of a large number of life forms. This has led to a grim biodiversity scenario, pushing numerous important plant and animal species to the verge of extinction or threatened or to vulnerable status. This is more prevalent in tropical rain forests, known for the richest biodiversity in the globe. Due to unplanned developmental activities, large blocks of contiguous forests are being reduced to remnant patches of secondary habitats, affecting the ecology and biodiversity. The impacts of these human induced changes are evident from extinction of species and increased population of exotic/invasive species (Daniels, 2003), vast stretches of barren lands, barren hill tops, reduced water infiltration and lowering of water table with ever increasing demand for water.

Rapid loss and degradation of primary forest habitat has led to the erosion of both biotic and abiotic components of the ecosystem, hampering the ecosystem functionality and hence probably reduced in productivity. Implications of the changes in ecosystem structure, function, and distribution, due to global climatic changes and/or land-use practices have raised serious concerns and also brought a paradigm shift in the approach towards ecosystem from human versus ecosystem to human and ecosystem along with the concept of ‘sustainable development' in conservation and management of natural resources.

The primary step taken towards conservation and management measures is to preserve a small proportion of forest and declare it as bioreserve, wildlife sanctuary and/or national park. The criteria followed in this regard, involved prioritising regions based on naturalness, diversity, rarity and or uniqueness, and size. Such planned actions were aimed at preserving and conserving biodiversity and natural resources of a region/nation or at larger scale contributing to global biodiversity. At the same time, it helps in improving local biodiversity and the environment in and around such areas in a natural and protected environment.

For effective management of biodiversity and conservation, there is a need to prioritise areas, especially those, which are considered most essential for conservation, i.e., biodiversity-priority areas. The process of prioritisation can be started with protected areas. Though at initial stages, protected areas were established on an ad hoc basis, with little attention to the conservation value of an area (Ramesh et al., 1997), but are quintessential for effective conservation and management practices.

In India, a survey was carried out in 1984-1987, to understand the requirements/needs of the protected areas (PAs) with the objectives to document, analyse and to provide information to public on the flora, fauna and habitats of these protected areas as well as laws, policies, practices, problems encountered in the management of protected areas and recommendations for improved management. This endeavour has resulted in the development of first national database on the management of national parks and sanctuaries in India . The Directory of National Parks and Sanctuaries in India (Variava and Singh 1985), published based on the survey, provides the basic information about most of the PAs in India , with maps. Simultaneously, directories of national parks and sanctuaries of each state were prepared, using the basic database (Singh et al. , 1990; Pande et al., 1991; Lal et al., 1994). Also, to give protection to a particular species of utmost importance, viz ., endemic, endangered, threatened, etc., several wildlife projects like, Project Tiger, Project Elephant, Project Gaur, Project Hungul, Project Rhinoceros, etc., were undertaken.

The areas having significant conservation value are declared as national parks and wildlife sanctuaries under the Wildlife (Protection) Act, 1972, which was amended in 1991. The Act specifies that, the state governments are empowered to declare any area as a sanctuary or a national park as per the procedures, for the purpose of protecting, propagating or developing wildlife or its environment. Under Section 18, the government may notify/declare any area to be a sanctuary, if it considers that such area is of adequate ecological, faunal, floral, geomorphological, natural or zoological significance. The first National Park in India was created in 1936 and named as the Hailey National Park in Uttar Pradesh, now known as Corbett National Park . India currently has 502 Wildlife Sanctuaries, 94 National Parks, and 14 Biosphere Reserves. These protected areas have helped to conserve a significant part of the biodiversity, currently covering an area of 156,586 sq.km, encompassing about 20% of the country's forest area and 4.76% of total land area.

The Western Ghats comprise a total area of 160,000 sq.km containing two Biosphere Reserves, eight National Parks and 39 Wildlife Sanctuaries in six states: Gujarat , Maharashtra , Goa , Karnataka, Tamil Nadu and Kerala. This region is broadly grouped as northern (covering Surat in Gujarat to Goa), central ( Goa to Nilgiri mountain in Tamilnadu) and southern Western Ghat (South of Palghat) (Pascal, 1988). Two thirds of the species found in the Western Ghats are endemic; nearly 1500 plants and 285 vertebrate species are endemic to this region. Endemic species like, Nilgiri Tahr, Lion-tailed Macaque, Nilgiri Langur etc., are extensively studied for their habitat preferences, feeding and reproductive behaviour and adverse effect on their habitat. Most of the endangered and vulnerable species like, Tiger, Asian Elephant, Dhole etc., are also studied on the same line (Daniels, 2003).

The Western Ghats cover 38,019 sq.km in the state of Karnataka (State of Forest report, FSI, 1987 and 1993). It has 5 National Parks and 15 Wildlife Sanctuaries (Table 1) and a part of Nilgiri Bioshpere Reserve. The National Parks and Wildlife Sanctuaries present in this area are treasure-trove of flora and fauna.  

Changes in vegetation cover arising from human land-use patterns, deforestation and succession, impacted ecological processes at various spatial and temporal scales has necessitated the understanding of dynamics of land-use and land-cover for sustainable management. In this direction, few attempts were made in the protected areas like, the application of remote sensing to classify vegetation and to determine land-cover change was made at the Kalakad-Mundanthurai Tiger Reserve. The degree of disturbance experienced based on their spatial correlation with a variety of potential disturbance causing factors was studied in Biligiri Rangaswamy Temple Wildlife Sanctuary (Menon and Bawa, 1997).

The National Parks and Wildlife Sanctuaries have been studied for ecological significance and to implement measures to conserve endemic and endangered species of flora and fauna. The habitat preferences of larger carnivores and their relationship with the prey species (herbivores) in Bandipur (Johnsingh, 1983) and Nagarhole National Park (Karanth, 1993) have been reported. However, there are no studies on ecological status in Sharavathi Valley Wildlife Sanctuary (SVWS) apart from case specific behavioural studies in few pockets of the sanctuary. In this regard, field investigation was carried out for a period of 24 months in the river basin, to assess the biodiversity and ecological status of the basin including SVWS.