Contributions to Zoology, 76 (3) – 2007K.A.I. Nekaris; S. Jaffe: Unexpected diversity of slow lorises (Nycticebus spp.) within the Javan pet trade: implications for slow loris taxonomy

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Since the 1950s, Sundaland (Borneo, Java, Sumatra and their surrounding islands) was thought to be inhabited by a single slow loris species, the greater slow loris Nycticebus coucang. Early taxonomies as well as recent morphological and genetic studies, however, point to at least three species native to this region: N. coucang, N. menagensis, and N. javanicus. In the light of this taxonomy, all Sundaland slow lorises, previously considered Least Threatened, have been listed as Vulnerable or Endangered. Of particular concern is the fact that slow lorises are the most common protected primate species in the rampant Southeast Asian pet trade, resulting in their recent transferral to CITES Appendix I precluding all international commercial trade. Due to lack of knowledge regarding morphological differences between the three species, they are still managed as one, with potential serious affects to wild populations, as hard-release of individuals of unknown geographic origin is common. This paper examines morphological variability of 34 live slow lorises, all of which were rescued from the wildlife trade in Java, Indonesia. Morphometric data and diagnostic images were collected, various species descriptions were considered and statistical analyses were conducted and compared with other taxonomists’ classifications. A discriminant function analysis provided support for four distinct groupings: Nycticebus coucang and N. javanicus, as well as evidence for two new taxa that correspond closely to N. hilleri and N. ornatus. The morphological traits that varied significantly and the external characteristic trends described in this study that contributed to these groupings might provide a baseline to classify Nycticebus taxa. This information is pertinent for appropriate captive management and specific designation of rescued individuals and for designing proper in-situ and ex-situ conservation strategies.