Ecological and anthropogenic covariates ... - GANGAPEDIA

Introduction
Humans live disproportionately near waterways and extensively modify riparian
zones (Sala, 2000). Consequently, species diversity of inland waters is among the
most threatened of all ecosystems and global freshwater biodiversity is declining at
far greater rates than is true for even the most affected terrestrial ecosystems (Sala,
2000). Habitat partitioning and microhabitat preferences may be evident among
crocodilians, especially when multiple species cohabit (Magnusson, 1985; Herron,
1994). Territoriality during the breeding season (Rootes and Chabreck 1993a);
reducing intraspecific competition (Hutton, 1989); or predator avoidance (Cott, 1961)
contribute to differential habitat use (Tucker et al 1997). Between 1997 and 2006, the
gharial population reportedly experienced a 58% drop across its range; and its total
breeding population was estimated to be less than 200 individuals, making it a
critically endangered species (IUCN, 2007). The gharial, is becoming increasingly
rare due to land-use changes, reduction in water flow, modification of river
morphology, loss of nesting sites, increased mortality in fishing nets and egg-
collection for consumption (Whitaker, 2007; Hussain, 2009); and is especially at risk
from flow regulation because it prefers fast-flowing river habitats, which are prime
sites for dams (Dudgeon, 2000). The gharial (Gavialis gangeticus, Gmelin, 1789),
endemic to the Indian subcontinent, was once common in the river systems of
Pakistan, northern India, Bangladesh, Myanmar, Bhutan and Nepal (Whitaker and
Basu, 1983; Whitaker, 1987, 2007; Hussain, 1999, 2009). However, they are now
restricted to a few, scattered locations in India and Nepal (Whitaker, 2007). The
gharial, is becoming increasingly rare due to land-use changes, reduction in water
flow, modification of river morphology, loss of nesting sites, increased mortality in
fishing nets and egg-collection for consumption (Whitaker, 2007; Hussain, 2009); and
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