WII study finds 586 saltwater crocodiles in Andamans
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Kolkata, Sep 18 : The Wildlife Institute of India (WII) recently detected 586 saltwater crocodiles in the Andaman and Nicobar Islands.
The saltwater crocodile (Crocodylus porosus) is the largest living crocodilian and inhabits a wide range of coastal habitats, including lagoons, deltas, estuaries, marshes, and creeks. Globally, the species is distributed across the Indo-Pacific region and occurs along the eastern coast of the Indian subcontinent in three disjunct populations in Odisha, West Bengal, and the Andaman and Nicobar Islands.
The “Conservation and Management Plan of Saltwater Crocodile (Crocodylus porosus) in the Andaman and Nicobar Islands” project was undertaken by the WII, under the directives of the Andaman and Nicobar Islands Integrated Development Corporation Limited (ANIIDCO) and in collaboration with the Andaman and Nicobar Forest Department.
A pan-island population estimation was conducted to assess the distribution and population status of saltwater crocodiles across the archipelago. Before actual fieldwork started, 536 personnel were trained across nine forest divisions. A total of 176 creeks were selected, of which 173 were successfully surveyed. Three could not be surveyed due to accessibility constraints.
“A dependent double-observer method was employed to count the crocodile population efficiently and also to estimate the detection probability of the observer. Fieldwork was completed in three closely spaced phases within a single season (February–March 2026), minimising the possibility of crocodile movement among creeks during the survey period and supporting the assumption of population closure,” the report said.
Researchers conducted four replicate surveys (two diurnal and two nocturnal) at each site to improve detection probability and account for observer bias. For each site, the minimum count (best count) was calculated as the maximum number of individuals observed cumulatively by both observers across replicates. We summed site-level best counts across all surveyed sites to derive a minimum estimate of the observed population.
Across the 173 surveyed creeks, we observed a total of 586 crocodiles. Crocodiles were detected in 91 creeks, representing 52.6 per cent of the surveyed sites. The study found that nearly 47 per cent of the total estimated saltwater crocodile population is concentrated in the Little Andaman and Nicobar division.
The results provide a detailed island-wide assessment of crocodile distribution and population status, which will help control human–crocodile conflicts. Between 1983 and 2023, the archipelago recorded 36 cases of fatal and non-fatal human–crocodile conflicts. Another study revealed that the conflict increased by 75 per cent after the 2004 tsunami.
Nearly 75 per cent of the attacks and sightings were recorded between June and December, considered the wet season in the islands. Some conflicts have been attributed to the presence of livestock near crocodile habitats, dumping of protein-rich food near creeks and beaches, particularly in tourist spots, and unchecked human activity close to the sites during the breeding season.
Authorities have asked researchers to study the reasons behind the increase in conflicts after the tsunami. The study will assist in better conservation efforts while protecting humans from attacks.
The saltwater crocodile (Crocodylus porosus) is the largest living crocodilian and inhabits a wide range of coastal habitats, including lagoons, deltas, estuaries, marshes, and creeks. Globally, the species is distributed across the Indo-Pacific region and occurs along the eastern coast of the Indian subcontinent in three disjunct populations in Odisha, West Bengal, and the Andaman and Nicobar Islands.
The “Conservation and Management Plan of Saltwater Crocodile (Crocodylus porosus) in the Andaman and Nicobar Islands” project was undertaken by the WII, under the directives of the Andaman and Nicobar Islands Integrated Development Corporation Limited (ANIIDCO) and in collaboration with the Andaman and Nicobar Forest Department.
A pan-island population estimation was conducted to assess the distribution and population status of saltwater crocodiles across the archipelago. Before actual fieldwork started, 536 personnel were trained across nine forest divisions. A total of 176 creeks were selected, of which 173 were successfully surveyed. Three could not be surveyed due to accessibility constraints.
“A dependent double-observer method was employed to count the crocodile population efficiently and also to estimate the detection probability of the observer. Fieldwork was completed in three closely spaced phases within a single season (February–March 2026), minimising the possibility of crocodile movement among creeks during the survey period and supporting the assumption of population closure,” the report said.
Researchers conducted four replicate surveys (two diurnal and two nocturnal) at each site to improve detection probability and account for observer bias. For each site, the minimum count (best count) was calculated as the maximum number of individuals observed cumulatively by both observers across replicates. We summed site-level best counts across all surveyed sites to derive a minimum estimate of the observed population.
Across the 173 surveyed creeks, we observed a total of 586 crocodiles. Crocodiles were detected in 91 creeks, representing 52.6 per cent of the surveyed sites. The study found that nearly 47 per cent of the total estimated saltwater crocodile population is concentrated in the Little Andaman and Nicobar division.
The results provide a detailed island-wide assessment of crocodile distribution and population status, which will help control human–crocodile conflicts. Between 1983 and 2023, the archipelago recorded 36 cases of fatal and non-fatal human–crocodile conflicts. Another study revealed that the conflict increased by 75 per cent after the 2004 tsunami.
Nearly 75 per cent of the attacks and sightings were recorded between June and December, considered the wet season in the islands. Some conflicts have been attributed to the presence of livestock near crocodile habitats, dumping of protein-rich food near creeks and beaches, particularly in tourist spots, and unchecked human activity close to the sites during the breeding season.
Authorities have asked researchers to study the reasons behind the increase in conflicts after the tsunami. The study will assist in better conservation efforts while protecting humans from attacks.
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Note: The content of this article is sourced from a news agency and has not been edited by the ap7am team.