The Wildlife Institute of India (WII) has recorded 586 saltwater crocodiles across the Andaman and Nicobar Islands, according to findings from a pan-island population survey completed between February and March 2026. The study, the most comprehensive of its kind conducted in the archipelago, offers a detailed island-wide assessment of distribution and population status of the saltwater crocodile (Crocodylus porosus) — the largest living crocodilian on the planet.

How the Survey Was Conducted

The survey was undertaken by the WII under the directives of the Andaman and Nicobar Islands Integrated Development Corporation Limited (ANIIDCO), in collaboration with the Andaman and Nicobar Forest Department. Before fieldwork commenced, 536 personnel were trained across nine forest divisions. Of 176 creeks selected for the survey, 173 were successfully covered — three could not be accessed due to terrain constraints.

Researchers employed a dependent double-observer method to count the population and estimate detection probability. To minimise the risk of crocodiles moving between survey sites, all fieldwork was completed in three closely spaced phases within a single season. Each site received four replicate surveys — two diurnal and two nocturnal — to improve detection accuracy and reduce observer bias. The minimum population estimate was derived by summing the maximum cumulative count from both observers across all replicates at each site.

Key Findings: Where the Crocodiles Are

Of the 173 surveyed creeks, crocodiles were detected in 91 creeks, representing 52.6 per cent of surveyed sites. Notably, nearly 47 per cent of the total estimated saltwater crocodile population is concentrated in the Little Andaman and Nicobar division, highlighting significant spatial clustering within the archipelago.

The saltwater crocodile inhabits a wide range of coastal habitats — lagoons, deltas, estuaries, marshes, and creeks. In India, the species occurs across three disjunct populations: Odisha, West Bengal, and the Andaman and Nicobar Islands. Globally, its range extends across the Indo-Pacific region.

Rising Human-Crocodile Conflict

The survey data also feeds into urgent conservation and safety concerns. Between 1983 and 2023, the archipelago recorded 36 cases of fatal and non-fatal human-crocodile conflicts. A separate study found that conflict incidents increased by 75 per cent following the 2004 tsunami, a pattern that researchers have been asked to investigate further.

Seasonality plays a clear role: nearly 75 per cent of attacks and sightings were recorded between June and December, corresponding to the islands' wet season. Contributory factors include livestock grazing near crocodile habitats, disposal of protein-rich waste near creeks and beaches — particularly at tourist sites — and unregulated human activity close to nesting zones during the breeding season.

Conservation and Management Implications

The findings form part of WII's 'Conservation and Management Plan of Saltwater Crocodile in the Andaman and Nicobar Islands' project. Authorities say the island-wide population baseline will support more targeted conflict mitigation strategies, habitat protection measures, and long-term conservation planning. With nearly half the population concentrated in one division, conservation resources can now be more precisely directed.

The study's methodology — multi-phase, multi-observer, multi-time surveys across a geographically complex archipelago — is expected to serve as a replicable framework for crocodile population assessments elsewhere in India.