Ecological and anthropogenic covariates ... - GANGAPEDIA

data also enables the estimation of various demographic parameters, vital rates and
state variables (e.g. Karanth 1995; Karanth & Nichols 1998; Karanth et al. 2006).
Although photographic identification of individual young gharials has been used in
captive conditions, this technique has not been adapted to field conditions. The goal
of this study is to demonstrate the feasibility (conceptual, technical and logistic) of
applying photographic capture-recapture techniques for estimating gharial abundance
in the wild. I describe a robust and easily replicable protocol for estimating gharial
population size using photo-capture of basking Gharials in the wild. Row-boat
surveys and stationary bank observations were undertaken to sample thirty 2.5 km
segments over 4 sampling occasions in the dry season from February to May, 2010, in
the National Chambal Sanctuary, Chambal River, India. I also explain in detail the
field challenges, precautions and methodology for conducting photo-identification of
Gharials.
Methods
Study Area
The 960 km long Chambal River rises in the northern slopes of the Vindhyan
escarpment, 15 km West-South-West of Mhow in Indore District in Madhya Pradesh
state, at an elevation of about 843 m (Jain et al. 2007). Lying between 24°55' and
26°50'N, 75°34' and 79°18'E the Chambal flows first in a northerly direction in
Madhya Pradesh(M.P.) for a length of about 346 km and then in a generally north-
easterly direction for a length of 225 km through Rajasthan. It flows for another 217
km between M.P. and Rajasthan (Raj) and further 145 km between M.P. and Uttar
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