The Terrestrial Herpetofauna of the Loyalty Islands!

The terrestrial herpetofauna of the Loyalty Islands, New Caledonia, is reviewed. This is the first comprehensive account of the reptile fauna of these islands since Roux's monograph on the region in 1913 and is based on recent collections made in August 1987 and a review of the collections made by Roux and Sarasin and housed in the Naturhistorisches Museum, Basel. Seventeen species of lizards and two species of snakes (one boid and one typhlopid) occur in the Loyalty Islands. Approximately half the lizard species are endemic to the New CaledoniaILoyalty Islands region, but only one, Emoia loyaltiensis (Roux), is endemic to the Loyalties alone. The remaining lizard species have widespread distributions throughout the Pacific. Most widespread species also occur on mainland New Caledonia, but several (Gehyra vorax Girard, Emoia cyanura [Lesson], and Candoia bibroni [Dumeril & BibronD do not. are covered by shallow bauxitic soils (Sautter 1981), and on Mare, small basaltic outcrops, representing emergent elements of the volcanic base of the Miocene reef, are also present (Paris 1981). The most substantial uplift of the islands was very recent, probably dating from the late Pleistocene (Paris 1981), and it seems likely that the Loyalties have been continuously emergent only since that period. Rainfall in the Loyalties is similar to that of the drier western part of the New Caledonian mainland. On Lifou, rainfall decreases from ca. 1700 mm per year in the north to under 1300 mm per year in the southwest (Sautter 1981). A similar trend affects Mare, whereas all of Ouvea experiences low precipitation (1200-1300 mm per year). There is no notable standing or flowing fresh water on any of the Loyalties, and most precipitation enters freshwater lenses within the permeable coralline substrate. In comparison with the more geologically complex New Caledonian mainland, the Loyalty Islands support a restricted range of vegetation types. Extensive stands ofAraucaria columnaris (Forster) occur on the southern coasts of both Lifou and Mare (Schmid 1981), and mangroves (Rhizophora spp.) are present in some areas. Coastal regions support typical littoral vegetation including coconuts and Casuarina, whereas inland areas are covered by humid forest. On Lifou, Schefflera spp. are among the dominant 76 THE LOYALTY ISLANDS lie in a line parallel to and ca. 110 km northeast of New Caledonia and 260 km southwest of the southern islands of Vanuatu (Figure 1). The Loyalties are separated from New Caledonia by the Loyalty Basin «2000 m depth) and from Vanuatu by the Vanuatu Trench (>7000 m depth). From northwest to southeast the major islands of the Loyalties are Ouvea (160 km2), Lifou (1150 km2), and Mare (650 km). Also included are a series of smaller islands, mostly lying between Lifou and Mare; the largest of these is Tiga. Walpole Island (lIe Walpole), located some 160 km southeast of Mare, is also an emergent island on the same extension of the Norfolk Rise but is often not included in discussions of the main Loyalty Group. All the islands are low-lying, with the highest elevation of 138 m near the southern point of the island of Mare. The islands are coralline in structure and are the remains of a Miocene reef situated atop a volcanic chain (Paris 1981, Sautter 1981). The raised rims of the islands represent uplifted coral reefs, and the interior regions of the islands are the uplifted lagoons or reef flats. On Lifou and Mare, parts of the interior I Manuscript accepted 15 April 1996. 2 Section of Herpetology, Australian Museum, 6-8 College Street, Sydney 2000, N.S.W., Australia. 3 Department of Biology, Villanova University, 800 Lancaster Avenue, Villanova, Pennsylvania 19085. Herpetofauna of the Loyalty Islands-SADLIER AND BAUER