HERPETOLOGICAL JOURNAL, Vol. 4, pp. 136-144 (1994) CONTRIBUTION TO THE SNAKE FAUNA OF THE SULU ARCHIPELAGO, WITH THE DESCRIPTION OF A NEW SUBSPECIES OF DENDRELAPHIS CAUDOLINEA TUS (GRAY, 1834) MAREN GAULKE Muhliusstrasse 84, 24103 Kiel, Germany On the islands of Bongao, Sanga Sanga, Siasi, Sibutu, and Tawitawi (all in the Sulu Archipelago) a total of 18 species/subspecies of land snakes were recorded. The observations on the different islands resulted in many new distribution records, 19 of which are published here for the first time: five for Bongao, four for Sanga Sanga, four for Siasi, and six for Tawitawi. One ofthe snakes (Boiga drapiezii drapiezii Boie, 1827) was not known before from the Philippines and the endemic subspecies Dendrelaphis caudolineatus flavescensnov. subsp. is described. The Sulu Archipelago shelters several endemic species/subspecies (e.g. Maticora intestinalis suluensis [Steindachner, 1891 ], Oligodon meyerinkii [Steindachner, 1891]). Other members of its land snake faunaare widely distributed on Borneo but occur nowhere else in the Philippines (B. d. drapiezii, Sibynophis geminatus geminatus Boie, 1827), while some are only known fromthe Philippines (Elaphe erythrura erythrura [Dumeril, Bibron & Dumeril, 1854], Chrysopelea paradisi paradisi Boie, 1826). INTRODUCTION MATERIAL AND METHODS Knowledge of the faunaof the Sulu Archipelago, During three excursions to the Sulu Archipelago in one of the most remote areas of the Philippines, is still 1990, 1991, and 1992 the following islands were vis­ fragmentary. The herpetological records are based ited: Bongao, Sanga Sanga, Siasi, Sibutu, and mainly on the investigations of E.H. Taylor, who ob­ Tawitawi (Fig. 1 ). The time spent on each of these is­ tained small collections of reptiles from several of the lands varied between almost three weeks on Sibutu, Sulu Islands some 70 years ago. This material resulted and less than a week on Siasi. Therefore the number of in range extensions for several species, and the de­ species which were detected on each island is corre­ scription of other new species and subspecies (Taylor, lated to the observation time, not the actual number of 1918a,b, 1919, 1922a,b,c, 1923). "Reptiles ofSulu Ar­ species present. Records are mainly based on chipelago" (Taylor, 1918a), lists 13 species of snakes sightings. If possible, specimens were caught forcloser for the Sulu Archipelago, with the highest number of examination and photographic records. A few speci­ records from the Bubuan/Tapaan group (five species, mens were preserved, including dead or badly injured including the sea snake Laticauda colubrina). Only on ones brought by inhabitants, and those which could not Jolo, the largest island of the Archipelago (345 square be identified in the field. Observations on habitat, rela­ miles), was a significant increase in the snake fauna tive abundance, and behaviour were recorded. The inventory made. While Taylor (1918a) recorded only fieldinvestigations were supplemented by examination Python reticulatus for Jolo, he foundseveral more spe­ of material from the herpetological collection of the cies in the following years (Taylor, 1918b, 1919, "Forschungsinstitut und Naturmuseum Senckenberg" 1922a,b,c, 1923). Leviton (1963) lists 13 land snake (SMF). Additional material for Tawitawi, collected by species for this island. On the other islands none or the Noona-Dan expedition from Denmark, which vis­ very few further records have been made. Even for ited the island in 1961, was examined in the Zoological Tawitawi, the second largest island (229 square miles), Museum in Copenhagen, Denmark (ZMUC). only two species of land snakes are listed in Leviton RESULTS (1963). Recent observations on the distribution of land The species recorded are listed below, and their pre­ snakes on some islands of the Sulu Archipelago are viously known and newly determined distribution given here, contributing considerably to their fragmen­ within the Philippines is given. New island records are tary snake lists. A new endemic subspecies of marked with an asterisk, and all the Sulu Islands are Dendrelaphis caudolineatus (Gray, 1834) is described. italicised. A species' occurrence on Borneo is men­ The dispersal routes of the listed snakes are discussed, tioned, but its distribution elsewhere in Asia is not emphasizing the special position which this island given since this is of little importance forthe discus­ group holds as a transitional zone between Borneoand sion of the direct zoogeographical relation of the Sulu the Philippines. Archipelago. SNAKE FAUNA OF SULU 137 6°N - -- - --... � \ D \ \ <?OcPsiasi \ c?Ji>o \ awitawi�B ubuan \ \ ............ SacgaSarg\_...... 6) {) ngao (.. Y.. r",.....:ibutu� � � � I Sitanki �)!\<:- \} I \. s \} FIG. l. Sulu Archipelago, generalized map of the study area. A list of the visited islands and their known land A. p. prasina (Boie, 1827) from Sibutu (in Gaulke, snake fauna, determined from the previous and new 1994, transferred to A. p. suluensis), and the Philip­ records, is added as Appendix I. pine subspecies A. p. preocularis (Taylor, 1922) from Jolo (in Leviton 1963 ). SPECIES LIST : Python reticulatus (Schneider, 1801). Boiga cynodon (Boie, 1827). Range: Basilan, Bohol, Bongao*, Cebu, Jolo, Leyte, Range: Basilan, Culion, Dinagat, Leyte, Luzon, Luzon, Mindanao, Mindoro, Negros, Palawan, Panay, Mindanao, Palawan, Polillo, Sibutu, Ta witawi* . Bor­ Polillo, Samar, Siasi*, Sibutu, Tawitawi. Borneo. neo. Remarks: The reticulated python is widespread in the Ma terial: SMF 74304, ZMUC R63877. Sulu Archipelago, and will certainly be found on sev­ Remarks: This large, nocturnal and aboreal cat snake eral more islands. It is not restricted to a special is reported from Sibutu (Gaulke, in press). Examina­ habitat. On Sibutu an adult specimen was observed in a tion of the Noona-Dan expedition material has also cave at the coastline, and on Tawitawi a juvenile was revealed a specimen from Tawitawi (ZMUC R63877). seen in secondary forest. On Bongao and Siasi pythons In spite of its wide distribution in Southeast Asia, the were kept as pets by villagers, who had caught them poorly known dog-toothed cat snake, seems to be con­ near their homes. However, I was informed by inhabit­ fined to primary forest. Since deforestation is almost ants that the populations are decreasing because of complete on the islands of the Sulu Archipelago, it continued hunting for its skin. must be considered as endangered in the region. Ahaetulla prasina suluensis Gaulke, 1994. Boiga drapiezii drapiezii (Boie, 1827). Range: Bongao, Sanga Sanga, Siasi, Sibutu, Ta witawi. Range: Tawitawi* . Borneo. Material: SMF 74298-9, 74844-5, 74870-2, 75059-60, Material: ZMUC R63 l l 70. 7523 1. Remarks: The Noona-Dan expedition material con­ Remarks: This recently described subspecies of the tains a juvenile Boiga from Tawitawi (ZMUC Malaysian vine snake is one of the most common R63 l l 70), whose head and neck are unfortunately snakes on all of the visited islands. Like the other sub­ badly battered. The determinable features are as fol­ species, this diurnal, arboreal snake inhabits primary lows: About 255 ventrals, 140 subcaudals, and 19 and secondary forest, bushland and bamboo forest. It midbody scale rows. Dorsal colour light brown with 67 was observed several times at night sleeping on river­ dark transverse bars across the back, not extending side trees. It was seldom found on the ground, e.g. if onto the belly. Inconspicious lighter blotches on border crossing a trail. between dorsals and ventrals. Tail lighter than back, Malaysian vine snakes were reported from the Sulu without dark bands, but 20 whitish blotches both sides Archipelago previously, including the nominate race along border of ventrals. Belly slightly lighter than 138 M. GAULKE back, heavily powdered with darker speckles, dark Dendrelaphis caudolineatus caudolineatus (Gray, stripes along the edges. 1834). The closely related forms Boiga angulata (Peters, Range: Balabac, Busuanga, Candaraman, Palawan, 1861), Boiga d. drapiezii and B. d. schultzei Taylor, Sibutu. Borneo. 1923 are distinguished from each other by head Material: SMF 74296-7, 74375. scalation, and therefore the identity of the Tawitawi Remarks: The range of this snake in the Philippines is specimen cannot be determined by this fe ature. confined to the Palawan province and the westernmost Mindanao is the nearest locality from which the rare B. island group of the Sulu Archipelago, where it was re­ angulata is known, while on Borneo, which is much cently discovered (Gaulke, in press). This diurnal closer to Tawitawi, B. d. drapiezii occurs. On Palawan, snake is relatively common on Sibutu. It was mostly which like the Tawitawi group is geographically and observed climbing on bushes and trees in the forestand zoogeographically very close to Borneo, but geographi­ shrublands, and seldom seen on the ground. cally separated from the Sulu Archipelago, another subspecies of B. drapiezii occurs (B. d. schultzei). The Dendrelaphis caudolineatus jlavescens nov. subsp. relations between the three forms, especially the spe­ Range: Bongao*, (Bubuan ), Sanga Sanga*, cific status of Philippine B. angulata, are still under Tawitawi*. The island in parenthesis is a distribution discussion (see Leviton, 1970). Because of the close record for D. modestus Boulenger, 1894 (now D. c. faunistic relationbetween Tawitawi and Borneo, the modestus) given by Taylor (l 922a). As the discussion complete geographic separation from Palawan, and the will