A review of the bat fauna of Con Dao national park, Southern Viet Nam

JOURNAL OF SCIENCE OF HNUE Natural Sci., 2011, Vol. 56, No. 7, pp. 138-143 A REVIEW OF THE BAT FAUNA OF CON DAO NATIONAL PARK, SOUTHERN VIETNAM Dao Nhan Loi, Pham Van Nha Tay Bac University Cao Thi Thanh Nga Vietnam Academy of Social Science Vu Dinh Thong(∗) Vietnam Academy of Science and Technology (∗)E-mail: thong@iebr.ac.vn Abstract. This paper presents the most updated information with taxo- nomic remarks on the Bat Fauna of the Con Dao National Park (CDNP). To date, a total of sixteen Bat species are known from this archipelago. Of which, records of nine species included in previous publications remain un- certain and require intensive examinations. Hipposideros larvatus appears as the most common Bat species within CDNP. It was frequently captured at all trapping sites during the recent field surveys. The survey results provided records of two species (Rhinolophus pusillus and Kerivoula cf. hardwickii) new to the park. Considerably, echolocation frequencies of H. larvatus and R. pusillus in CDNP are over 10 kHz higher as compared with those from mainland areas. Keywords: Chiroptera, echolocation, Mammalia, taxonomy, Vietnam. 1. Introduction With a total area of 40.498 ha, CDNP is a well-known site for its not only high biodiversity values, but also historical and cultural profiles [6]. Results from previous biodiversity surveys included 13 Bat species belonging to 6 genera and 3 families [6]. It must be considerable that all previous records of Bats from CDNP remain uncertain as they were not referred to any primary material. Results from Bat surveys carried out at CDNP between 2008 and 2011 with taxonomic remarks on the previous records are given in this paper. 138 A review of the bat fauna of Con Dao National Park, Southern Vietnam 2. Content 2.1. Study sites and methods * Study sites CDNP contains a range of landscapes, including caves and tunnels. The recent Bat surveys were mainly carried out at 4 sites, namely Hang Duong Cemetery, Voi Fireplace (Lo Voi), Ong Dung Wharf (Ben Ong Dung) and Duc Me Temple. * Methods - Bat capture and measurements: All bats were captured using mist nets con- sisting of various sizes (3 m in height, from 3 m to 12 m in length) and four-bank harps. The nets and traps were set across footpaths and narrow streams in the forest. The following measurements were taken in the field using digital calipers ac- curate to the nearest 0.1 mm: FA, forearm length - from the extremity of the elbow to the extremity of the carpus with the wings folded; EH, ear height - length of ear conch; EW, ear width - the greatest width of earconch. The above measurements are described and illustrated by Bates and Harrison [8]. Body mass (W) was also taken in the field using a 50 g LightLine Spring balance. Juveniles and pregnant females were excluded from analyses to reduce the influence of seasonal variations in body mass. All voucher specimens are preserved in the collection of Vu Dinh Thong at the Institute of Ecology and Biological Resources (IEBR). - Echolocation recording and analysis: Echolocation calls were obtained from recordings using the PCTape system at a sampling rate of 480 kHz while Bats were resting on the wall of a flight-tent (4 m [length] × 4 m [width] × 2 m [height]). Batman software was used to obtain high quality sound sequences. All echolocation signals were analysed using the Selena software to measure the constant frequency of the second harmonic (CF) of each call. The PCTape system, Batman and Se- lena softwares are custom-made by the University of Tbingen, Germany. All sound recording and analysis processes were carried out by Vu Dinh Thong. 2.2. Results and discussions 2.2.1. Bat species known from CDNP With data from literatures and materials collected from recent surveys, a total of 16 species belonging to 7 genera are known from CDNP (Table 1). Of which, Pteropus hypomelanus and Rhinolophus chaseni are two of the rarest Bat species in Vietnam. 139 Dao Nhan Loi, Cao Thi Thanh Nga, Pham Van Nha and Vu Dinh Thong Table 1. Bat species currently known from CDNP Species Recorded in Scientific name English name Pteropodidae Bonaparte, 1838 Old-World fruit bats Pteropus hypomelanus Temminck, 1853 Small flying fox [6] - P. Vampyrus (Linnaeus, 1758) Large flying fox [6], - Macroglossus minimus (Geoffroy, 1810) Common long-tongued fruit bat [3, 6, 7] M. Sobrinus Andersen, 1911 Hill long-tongued fruit bat [3], - Emballonuridae Gervais, 1855 Sheath-tailed bats Taphozous melanopogon Temminck, 1841 Black-beared tomb bat [1] Megadermatidae Allen, 1864 False vampire bats Megaderma spasma (Linnaeus, 1758) Lesser false vampire bat [6], m Rhinolophidae Gray, 1825 Horseshoe bats Rhinolophus luctus Temminck, 1835 Woolly horseshoe bat [1] - R. Lepidus Blyth, 1844 Blyths horseshoe bat [1] - R. Pusillus Temminck, 1834* Least horseshoe bat m R. Chaseni Sanborn, 1939 Indochinese horseshoe bat [6], m R. Thomasi Andersen, 1905 Thomass horseshoe bat [3], - Hipposideridae Miller, 1907 Old-World leaf-nosed bats Hipposideros ater Templeton, 1848 Dusky leaf-nosed bat [3], - H. Larvatus (Horsfield, 1823) Horsfield’s leaf-nosed bat [1, 6], m H. Diadema (Geoffroy, 1813) Diadem leaf-nosed bat [1], - H. Bicolor (Temminck, 1834) Bicolored leaf-nosed bat [6], - Vespertilionidae Gray, 1821 Evening bats Kerivoula cf. hardwickii (Horsfield, 1824)* Woolly bat m Notes. *: new record to CDNP; -: Unconfirmed record; [ ]: Ordinal number in the reference section; m: specimen held at IEBR. 2.2.2. Taxonomic remarks and conservation status * Old-World Fruit Bats (Pteropodidae) A previous publication included a record of the Large flying fox (Pteropus vampyrus) from CDNP without reference to any primary material [6]. Remarkably, a comprehensive review of the Flying Fox research in Vietnam [9] excluded CDNP from the confirmed distribution range of P. vampyrus. To date, there is no solid 140 A review of the bat fauna of Con Dao National Park, Southern Vietnam evidence to confirm the distribution of Pteropus vampyrus in CDNP. In 1869, Peters classified materials from Con Son Island as an endemic Fly- ing Fox species of Vietnam, namely P. condorensis [9]. However, this taxon was subsequently reclassified as a subspecies of the small Flying Fox (P. hypomelanus condorensis). It is clear that the taxonomic status of P. condorensis still remains uncertain and requires further examinations. Another Fruit Bat species, Macroglossus minimus, was also recorded from CDNP in the 1960s [7]. Remarkably, no subsequent record of this species was obtained from CDNP. * Sheath-tailed Bats (Emballonuridae) Black-beared tomb bat (Taphozous melanopogon) has been recorded almost everywhere throughout Vietnam [7]. To date, the only record of Black-beared tomb bat from CDNP was published in 2003 [1]. False Vampire Bats (Megadermatidae) Lesser false vampire bat (Megaderma spasma) was first recorded from CDNP in 2004 [6]. An individual of this species was also captured at Ong Dung Wharf (Ben Ong Dung) trapping site over our field survey in 2008. Horseshoe Bats (Rhinolophidae) Bornean Horseshoe Bat (Rhinolophus borneensis) together with two leaf-nosed Bat species (Hipposideros bicolor and H. larvatus) were included in a previous pub- lication but misclassified into the same family Rhinolophidae [6]. According to the current classification systems, they belong to two distinct families [1, 4, 8]. Remark- ably, materials from CDNP, which had been misidentified as Rhinolophus borneen- sis, are currently reclassified as Rhinolophus chaseni [2] based on achievements in molecular and echolocation researches. It also means that all records of Rhinolophus borneensis from Vietnam are henceforth invalid. A record of Blyths Horseshoe Bat (Rhinolophus lepidus) from CDNP included in a previous publication [1] also remain uncertain. In fact, almost all morphological features of Rhinolophus lepidus are similar to those of Rhinolophus pusillus [5]. Vu Dinh Thong indicated that materials of Rhinolophus pusillus were misidentified as Rhinolophus lepidus in a range of publications (personal communication). Eviden- tially, several individuals of Rhinolophus pusillus collected during the recent surveys at CDNP are similar to Rhinolophus lepidus in morphology. Therefore, an intensive examination of the record of Rhinolophus lepidus from CDNP is clearly needed. Old-World Leaf-nosed Bats (Hipposideridae) Of the four leaf-nosed Bat species known from CDNP, records of three species 141 Dao Nhan Loi, Cao Thi Thanh Nga, Pham Van Nha and Vu Dinh Thong (Hipposideros bicolor, Hipposideros ater and Hipposideros diadema) included in pre- vious publications seem improper [1, 3, 6] as they were not referred to any primary material. In fact, because of their morphological similarity, taxonomists frequently face difficulties in identification of small leaf-nosed Bat species. To date, Hip- posideros larvatus is the only Leaf-nosed Bat species with solidly confirmed records from CDNP. Evening Bats (Vespertilionidae) A juvenile of the genus Kerivoula was collected from CDNP and appears as the first record of the Woolly Bat from this archipelago. The specimen is provisionally identified as Kerivoula cf. hardwickii. Table 2. External measurements, body mass and echolocation frequencies of selected Bat species from CDNP Species W FA EH EW CF Rhinolophus 3.8 ± 0.4 37.8 ± 0.9 14.7 ± 0.8 11.3 ± 0.6 115.2 ± 1.5 pusillus (3.0 - 4.0) (36.6 - 39.0) (13.5 - 15.5) (10.5 - 12.0) (113.4 - 115.2) 5 6 6 6 4 6.4 ± 0.8 42.9 ± 1.0 18.4 ± 1.2 13.5 ± 1.4 77.8 ± 1.0 R. Chaseni (4.0 - 8.0) (40.3 - 44.8) (15.3 - 20.5) (11.0 - 18.0) (76.2 - 80.7) 20 21 21 19 20 Hipposideros 12.9 ± 1.5 56.1 ± 1.5 20.6 ± 0.6 18.5 ± 0.6 100.4 ± 3.3 larvatus (10.0 - 15.0) (52.5 - 60.5) (19.0 - 22.0) (17.0 - 19.5) (95.3 - 1004.6) 44 50 50 47 44 Note: Data is given as mean ± standard deviation, range and sample size, W: body mass; FA: forearm length; EH: ear height; EW: ear width; CF: constant frequency Echolocation frequencies of R. pusillus and H. larvatus from CDNP are much higher in comparison with those from other localities (Table 2). The results suggest geographic variations in echolocation calls of these two species. 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