View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by ScholarSpace at University of Hawai'i at Manoa Reptiles of Fais Island, Yap State, Federated States of Micronesia1 Donald W. Buden2 Abstract: Eleven species of reptiles (six skinks, four geckos, one monitor lizard) are recorded from Fais Island, Micronesia, four of them (Gehyra mutilata, Lepi- dodactylus moestus, L. sp., and Eugongylus albofasciolatus) for the first time. The skinks Emoia caeruleocauda and E. jakati are the most common species; G. muti- lata is the most common gecko in edificarian habitats, andL. moestus is the most common outside the areas of human habitation. Nearly all of the species are widespread in the western Pacific region, although Eutropis sp. is at the eastern- most limits of its distribution in the Caroline Islands on Fais. The monitor lizard Varanus indicus was introduced during the Japanese administration. The other species may have arrived by natural dispersal, or by human assistance, or a com- bination of the two. Little is known of the biota of Fais Island, Frankfurt, Germany (digital printout of col- Micronesia, and information on terrestrial lections, courtesy of G. Koehler and L. vertebrates is especially scanty. Steadman and A cker). The only other mention of reptiles on Intoh (1994) reported on the avifauna, focus- Fais are passing remarks in several nonbio- ing almost entirely on archaeological remains. logical articles alluding to a large lizard (re- Native mammals are absent, but Kramer ferred to in one account as a monitor lizard), (1937) recorded dogs (Canis familiaris) and and almost certainly all pertaining to Varanus rats (Rattus sp.), Intoh and Shigehara (2004) indicus. discussed the archaeological history of dogs This study was undertaken mainly to shed and pigs (Sus scrofa) on the island, and Intoh additional light on the distribution and rela- (2008) commented further on dogs, pigs, and tive abundance of reptiles on this remote and rats also from an archaeological perspective. biologically poorly known Pacific outpost. Information on the herpetofauna is almost The results of contemporaneous ancillary entirely limited to Sternfeld’s (1920) remarks surveys of birds, butterflies, and dragonflies on 44 specimens of five species of skinks and will be reported elsewhere. one gecko collected by E. Wolf on Feis (=Fais) in 1909, during the 1909 – 1911 Hanseatic South Seas Expedition. The names of six Study Area skinks are listed in the Sternfeld report, but Lygosoma sorex Boettger and L. kordoanum Fais (9° 46′ N, 140° 31′ E) is a small (2.9 by 2 Meyer are synonyms of Emoia caeruleocauda 1.2 km, 2.8 km ), low (28 m) raised coral is- (De Vis) (see Brown 1991). At least 40 of the land in the west-central Pacific Ocean. It is 44 specimens are in the Senckenberg Museum, approximately 210 km east of the main islands of Yap proper and 80 km east of Ulithi Atoll, which is the nearest land (Figure 1). Fais is a part of Yap State, within the Federated States 1 Manuscript accepted 4 July 2010. of Micronesia (FSM), which includes (from 2 Division of Natural Sciences and Mathematics, Col- lege of Micronesia — FSM, P.O. Box 159, Kolonia, Pohn- west to east) Yap, Chuuk, Pohnpei, and Kos- pei, Federated States of Micronesia 96941 (e-mail: don rae states. The FSM, together with the Re- [email protected]). public of Belau (Palau) immediately to the west, make up the Caroline Islands. Topo- graphically, Fais has a 100 to150 m wide but Pacific Science (2011), vol. 65, no. 2:277 – 283 doi: 10.2984/65.2.277 discontinuous coastal belt that rises abruptly © 2011 by University of Hawai‘i Press (15 – 20 m) in many places to a central plateau; All rights reserved shear cliffs rise directly out of the sea along 277 278 PACIFIC SCIENCE · April 2011 Figure 1. Location map for Fais Island and surrounding islands. the northwestern and southeastern shores materials and methods (Figure 2). Chamisso (1821:183) described Fais as having the most luxuriant flora of any Fieldwork was conducted during 17 – 21 De- island in the Carolines. However, much of the cember 2007 and 23 – 29 June 2009; 134 spec- original forest and the face of the central pla- imens of nine species of lizards were collected teau doubtlessly were decimated during ex- by hand and preserved. Most of the specimens tensive phosphate mining operations in the were fixed in 10% formalin and later trans- later years of the Japanese administration, ferred to 35% isopropanol. Tissue samples, from 1938 to 1944 (Intoh and Yamaguchi and in several instances whole specimens, of 1996). The forest has since been supplanted Emoia jakati, Eutropis sp., and Lepidodactylus by scrub, secondary woodland, grassland, and spp. were preserved in ethanol for later DNA farmland. Remnant forest dominated by Bar- analysis. Specimens were deposited in the ringtonia asiatica is found mainly along the rim California Academy of Sciences; Museum of of the circumferential cliffs. A more detailed Comparative Zoology, Harvard University; assessment of the flora and vegetation is pro- National Museum of Natural History, Smith- vided by Fosberg and Evans (1969). sonian Institution; and the U.S. Geological Reptiles of Fais Island · Buden 279 Figure 2. Fais Island localities (adapted from Gajdusek 1976). Survey, San Diego Field Station. Terms of where. Of the 36 specimens collected, 35 are abundance are based on incidental observa- from buildings in the settlement and one is tions and estimated encounters per day: com- from a cliff face at the northern end of the is- mon (at least 30 sightings per day under opti- land. mum conditions), fairly common (usually 5 – 15 per day), uncommon (1 – 5 on most Gehyra oceanica (Lesson) days), scarce (fewer than four recorded sight- The oceanic gecko is fairly common through- ings, all surveys combined). out and found in a wide variety of habitats, including edificarian (mainly walls of build- results ings), forest (tree trunks), and scaevola shrubs along the beach. Geckos Gehyra mutilata ( Wiegmann) Lepidodactylus moestus (Peters) The stump-toed or mutilating gecko is com- The Micronesian scaly-toed gecko is espe- mon in edificarian habitats but scarce else- cially common in scaevola shrubs along the 280 PACIFIC SCIENCE · April 2011 beach at night, where it was also the most bust body with a dorsal pattern of alternating abundant gecko during this study. It was also dark brown and pale tan crossbars, short legs, encountered regularly but somewhat less fre- and sinuous body movements. Eugongylus al- quently in edificarian habitats and only occa- bofasciolatus is the only member of the genus sionally in forest. Sixteen of the 19 examples documented in the FSM. However, Crombie of Lepidodactylus collected during this study and Pregill (1999) indicated that the genus is are identified asL. moestus. in need of review; species limits and their re- lationships remain largely unresolved. Lepidodactylus sp. Three of the 19 specimens of the genus Lepi- Eutropis sp. dodactylus from Fais appear to be examples of The taxonomic status of the lizards on Fais an unidentified (and possibly undescribed) (and Ulithi Atoll) that Sternfeld (1920) re- b isexual species other than L. moestus. They corded under Mabuia (=Mabuya) multicarinata seem most similar to the undescribed sexual is unresolved. Crombie and Pregill (1999) species from Palau (in Crombie and Pregill suggested that these Caroline Islands popula- 1999) and to other specimens from Ngulu tions, together with those in Palau, may rep- Atoll in southwestern Yap State (Fisher, pers. resent an undescribed species closely allied to comm.). M. multicarinata, and that they probably reached the Caroline Islands via natural dis- persal from the Philippines and/or Borneo. In Skinks a recent revision of the genus Mabuya, Maus- Emoia caeruleocauda (De Vis) feld et al. (2002) resurrected the name Eutro- The Pacific blue-tailed skink is common pis Fitzinger for the Asia/Oceania species. A throughout Fais. It was usually seen on the subsequent genetic study (Mausfeld and ground and 1 – 2 m high in weeds and shrubs Schmitz 2003) supports the hypothesis that and on tree trunks. Although some showed the Palauan population represents an unde- the typical color pattern of three pale dorsal scribed species related to E. multicarinata, and stripes on a dark ground color, and juveniles that it probably colonized Palau by natural had distinctly blue tails, many of the adults I dispersal from the Philippines. The Fais/ observed were almost uniformly brown dor- Ulithi populations were not included in that sally and had only a faint indication of stripes study but are likely to fall within the Palauan that were often reduced to a vestige of the group on geographic grounds. middorsal stripe on the head. Eutropis sp. is probably fairly common to common throughout Fais, though appearing Emoia jakati (Kopstein) scarce at times. I observed it in a wide variety The Jakati skink is common in open, sparsely of habitats, including grasslands, croplands, vegetated areas as well as in leaf litter on the forest, coastal strand, and ruderal areas in the forest floor. It was most numerous in coconut settlement. I saw no more than five or six (all forest at the edge of the beach at Tariow Place presumed adults) during 17 – 21 December (25 were counted in 5 min [300/hr]), and 2007, none of which I was able to collect. But o thers may have been present but could not I saw many more and collected 20 during be confidently distinguished from darkly col- 23 – 29 June 2009, including 11 juveniles, the ored E. caeruleocauda when glimpsed briefly. smallest measuring 27.3 mm in snout – vent length and 10 others ranging from 30.9 to Eugongylus albofasciolatus (Gü nther) 34.6 mm.