Status, distribution and conservation of crocodiles in Sri Lanka

Abstract

Two species of crocodile occur in Sri Lanka, namely the marsh crocodile ( Crocodylus palustris) and the estuarine crocodile ( Crocodylus porosus), confined largely to the low-country in the first peneplain. Both species have declined in range and number since the turn of the century, mainly through over-hunting for hide and meat in the past, and conversion of their habitat to other land-uses by man at present. They have been completely extirpated from the Jaffna peninsula in the north. The study on the status and distribution of crocodiles was carried out from 1991 to 1996 during which crocodiles were recorded from 113 localities, 105 of which were inhabited by the marsh crocodile ( C. palustris), while 33 localities harboured the estuarine crocodile ( C. porosus). The two species were sympatric in 25 localities. Of the 105 localities from which C. palustris were recorded, it was considered rare in 62, common in 35, abundant in five, and perhaps extinct recently in three. Of the 41 large river systems, 32 were found to support crocodiles. Both species of crocodile are particularly abundant and secure in the country's two premier conservation areas: the Ruhuna National Park in the south-east and the Wilpattu National Park in the north-west. It is estimated that there could be at least 1220 marsh crocodiles, and perhaps no more than 300 estuarine crocodiles in Sri Lanka. Crocodiles are being threatened by indiscriminate destruction of the island's mangroves and marsh vegetation for human habitation and prawn farming. In Sri Lanka, the marsh crocodile is known to tolerate concentrations of salt higher than that in sea water for a long time. The estuarine crocodile is known to move a considerable distance in land from the coast. The strong territorial behaviour among the male estuarine crocodiles may perhaps help space the individuals. Crocodiles have a poor image in Sri Lanka. Most rural people consider them a serious and potentially dangerous pest and so do not regret their disappearance from their neighbourhood. Marsh crocodiles can be ranched, but the concept of sustainable utilization of wildlife in general is still anathema to a large segment of the population in Sri Lanka. On the other hand, if crocodiles could benefit people, they are not likely to become extinct.