The Gharial Gavialis gangeticus Gmelin (1789) is endemic to the Indian subcontinent and historically occurred in the Indus, Ganges, Mahanadi, Brahmaputra and Irra-waddy River systems (Smith 1939). In the 1970s, the gha-rial population was estimated at <200 (Whitaker et al.1974), following which a conservation initiative involvingcreation of protected areas and rear-and-release pro-grammes was established. The subsequent recovery of the population was short-lived with the cessation of central government funding. By 2006, the gharial population reportedly experienced a 58% drop in numbers across its range; the total breeding population was estimated to be about 200 individuals, largely restricted to scattered locations in India and Nepal, and the global population, as a single unit, met the International Union for Conservation of Nature criteria for Critically Endangered (Choudhury et al. 2007). The Chambal River in India has the single largest contiguous population, reportedly between 48%and 85% of the global population (Choudhury et al.2007; Hussain 2009). The gharial is threatened by riverbank land-use changes, reduction in river flows, modification of river morphology, loss of nesting and baskingsites, increased mortality in fishing nets and egg-collection for consumption (Whitaker & Members of the GMTF2007; 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).Boat-based daylight gharial surveys, to date, only pro-vide indices of relative abundance, without measures ofsurvey bias or error. No attempt to quantify detection probabilities in these surveys has yet been made, and thus,absolute density estimates of this population remain unknown. Despite the release of over 5000 gharials into various Indian rivers over the past few decades, as part ofthe rear-and-release programmes, only about 200 breeding adults reportedly still survive (Choudhury et al. 2007),and this poses serious questions about age- and size-spe-cific survival rates. These programmes lacked monitoring of survival and dispersal of released animals and hence the efficacy of this programme could not be evaluated. In this scenario, the estimation of absolute abundances can help assess the restocking programme, provide information on the current status of gharials and inform future conservation strategies.The various survey techniques used to ascertain crocodil-ian populations world-wide, reviewed by Magnuson (1982)and Bayliss (1987), vary greatly in terms of applicability,cost-effectiveness, the species involved, and the socio–political and administrative environment. Conventionalmark–recapture techniques, besides being affected by theabove, also suffer from tag loss and unequal catchability(Bayliss 1987); altered natural behaviour (Gauthier-Clercet al. 2004) and ethical and welfare issues arising from theapplication of tags or marks (Wilson & McMahon 2006).The use of natural markings to distinguish between individuals has been used for the identification of chim-panzees from facial characteristics (van Lawick-Goodall1971); dolphins from dorsal fin cuts and nicks (Mazzoilet al. 2004); Nile crocodiles (Swanepoel 1996); African wild dogs from coat markings (Creel & Creel 1995); tigers from stripe patterns (Karanth 1995) and the use of pat-tern recognition software to identify cheetahs (Kelly 2001)and whale sharks (Arzoumanian, Holmberg & Norman2005) from spot patterns. Individual identification, used within the framework of capture–recapture analysis, pro-vides a statistical framework for estimating p (detection orcapture probability) and quantities of biological interest such as population size (Nichols 1992).Our objectives were to determine whether individual gharials were identifiable in the wild; and if individuali dentification could be used to estimate populations ofwild crocodilians. Our approach fills an important gap ingharial monitoring and population estimation by combin-ing photo-identification and capture–recapture techniques.This is the first such attempt for estimating crocodilian abundance in the wild. Our results shed new light on the gharials population status in the Chambal River and have major conservation implications in view of current man-agement objectives and species recovery efforts.