The Ecology Of False Gharial (Tomistoma schlegelii Mueller)

Introduction
Though known for over a century as a museum specimen, the false gharial, Tomistoma schlegelii, has remain somewhat a mystery in terms of its distribution and abundance. A cryptically coloured and secretive species, the inaccessibility of its swampy habitat makes it difficult to detect. Lack of interest could also be caused by the species having no local cultural importance nor any significant economic value (the skin is not traded locally). Thus the distribution and status of T. schlegelii in Sarawak has yet to be properly documented, and the species has received little attention its listing among Sarawak's protected wildlife.

Distribution
In Sarawak, false gharials could be found in the upper Rejang, Tutuh, Suai, Tisak, Seterap, Kelauh, Sg. Dor in Engkelili, Sg. Ensengei Baki and Sg. Runjing. However the presence of the species in Loagan bunut (Oxbow lake) has not been proven.

Firsthand reports from western Sarawak are numerous, most of them from swampy tributaries of the Lupar and the Sadong Rivers, such as the Sg. Ensengei Baki (Table 1). The wxistence of the species in the Ensengei Baki, Serian was confirmed by Engkamat L. in his 1996 survey. The most recent attack by a female false gharial occurred in Sg. Kroh, Engkelili in June 1999.

Habitat and Nesting

The majority of T. schlegelii in Sarawak are from peat swamps found in the interior tributaries of the Sadong, Lupar and Tatau/Kakus rivers. Vegetation is composed of a giant species of Pandanus, and the river channels are often blocked debris and by large floating mats of Hanguana malayana.

For nesting areas, conditions observed at the Sg. Runjing nest suggest that forest cover is an important feature of nesting areas. Unlike Crocodylus porosus, T. schlegelii apparently avoid the sun, and if given the opportunity, choose to rest in the shade when out of the water.

A nest found in Sg. Runging was constructed in dsiturbed peat swamp forest, at the base of a tree in relatively deep shade about 2 m from the stream bank. The nest materials were dry leaves and woody debris. The false gharial nest was not built as an isolated mound (like nests of most C. porosus), but was constructed at the base of a tree.

Conservation
From the most recent spotlight surveys and interviews with local people, densities of false gharials seem rather low, though the animals are always difficult to detect. A matter of great concern for long-term survival of T schlegelii populations is the impact of land development on peat swamps and their associated rivers in Sarawak, especially the area from Serian to Engkelili.

Currently, there are no gazetted or protected areas lying within the core distribution T. schlegelii in Sarawak. The Maludam National Park (43,147 ha.), where T. schlegelii may occur, has been on the proposed list for several years, and it is currently on its final stage of gazettement. This proposed National Park may, in fact, le outside the areas historically having the highest density of T. schlegeli in Sarawak.

Considerable conservation effort has been underway over the last few years to promote legislation to discourage all forms of hunting and wildlife trade in Sarawak. Unfortunately, species such as Tomistoma schlegelii will benefit more from guidelines on sustainable use of resources and wise land use, rather than a ban on killing, trading and farming.