THE STATUS OF OTTERS (CARNIVORA : MUSTELIDAE : LUTRINAE) IN SINGAPORE AND MALAYSIA, AND THE DIET OF THE SMOOTH OTTER (LUTROGALE PERSPICILLATA) IN PENANG, WEST MALAYSIA

Abstract

The IUCN/SSC Action Plan for Otters (Foster-Turley et al., 1990) alerted the scientific community to the fact that the biology of otters is relatively unknown, particularly in Asia. In response to this plan, the conservation biology of otters in Singapore and Malaysia is herein addressed. Three aspects were studied, viz. the taxonomy and distribution of the Malaysian lutrines, as well as the diet of the Smooth Otter in a rocky shore habitat in Penang. The confusion over their taxonomy has lasted over a century and in Asia, four species are present Thus, prior to ecological studies, the problems in the taxonomy and nomenclature of the genera, species and subspecies had to be addressed. Four Asian taxa of otters are recognised, viz. the Small-clawed Otter, Amblonyx cinereus (Illiger, 1815); the Smooth Otter, Lutrogale perspicillata (Geoffroy, 1826); the Hairy-nosed Otter, Lutra sumatrana (Gray 1865); and the Southeast Asian form of the Eurasian otter, Lutra lutra barang Cuvier, 1823. Distribution studies were based mainly on the specimens in regional museums as well as that of certain European and American museums. The literature was highly unsatisfactory, being fueled extensively by misidentifications, poor taxonomy, and unsubstantiated claims. The results of the present study indicate there is no evidence of the Eurasian Otter ever being present in Peninsular Malaysia; earlier records were all traced to a specimen of L. perspicllata instead. In Sarawak, however, there are two specimens that attest to the presence of L. l. barang in Borneo, although its distribution was not previously believed to have included Borneo. While the Smooth and Small-clawed Otters are common in certain areas of the peninsula, and the latter is also common in parts of Borneo, the Hairy-nosed Otter is scarce, and the status of this Southeast Asian endemic may be critical. Information from Borneo is largely non-existent. With the taxonomy and distribution of the Malaysian otters verified, an investigation into the diet of a family group of Smooth Otters in Penang, Malaysia, was conducted over 15 months of periodic sampling and observations. The site was a 10.6 km coastline of rocky and sandy shores surrounding a forest reserve. The study revealed that the diet consisted of fish (100% occurrence) and partly of decapod crustaceans (24% occurrence). Besides this, no other animal components were found in the diet. There was also no evidence of seasonality. This contrasts with the other common species of otter in Malaysia, A. cinereus, which appears to feed largely on crustaceans. The observations and sprainting activity suggested the preliminary observation that otters focused their activities around a 2 km stretch of the study site.