First Records of 10 Bat Species in Guyana and Comments on Diversity of Bats in Iwokrama Forest
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View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by KU ScholarWorks Acta Chiropterologica, l(2): 179-190,1999 PL ISSN 1508-1 109 O Museum and Institute of Zoology PAS First records of 10 bat species in Guyana and comments on diversity of bats in Iwokrama Forest BURTONK. LIM', MARKD. ENGSTROM~,ROBERT M. TIMM~,ROBERT P. ANDERSON~, and L. CYNTHIAWATSON~ 'Centre for Biodiversity and Conservation Biology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada; E-mail: [email protected] 2Natural History Museum and Department of Ecology & Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045-2454, USA 3Centrefor the Study of Biological Diversity, University of Guyana, Turkeyen Campus, East Coast Demerara, Guyana Ten species of bats (Centronycteris-maximiliani,Diclidurus albus, D. ingens, D. isabellus, Peropteryx leucoptera, Micronycteris brosseti, M. microtis, Tonatia carrikeri, Lasiurus atratus, and Myotis riparius) collected in the Iwokrarna International Rain Forest Programme site represent the first records of these taxa from Guyana. This report brings the known bat fauna of Guyana to 107 species and the fauna of Iwokrama Forest to 74 species. Measurements, reproductive data, and comments on taxonomy and distribution are provided. Key words: Chiroptera, Neotropics, Guyana, Iwokrama Forest, inventory, species diversity on the first of two field trips that constituted the mammal portion of the faunal survey for The mammalian fauna of Guyana is Iwokrama Forest coordinated through The poorly documented in comparison with Academy of Natural Sciences of Philadel- neighbouring countries in northern South phia. Records from previously unreported America. Most of its species and their distri- specimens at the Royal Ontario Museum are butions are inferred (e.g., Eisenberg, 1989) also presented to augment distributional data. from mammals reported in Venezuela (e.g ., Handley, 1976) and Suriname (e.g., Husson, MATERIALSAND METHODS 1978). Two recent publications (Parker et al., 1993; Smith and Kerry, 1996) reported on Study Sites separate, small single-site collections from Fieldwork was conducted primarily from 9 March Guyana and indicate a renewed interest in to 12 April 1997 in the Iwokrama International Rain the diversity of Guyanese mammals. Herein, Forest Programme site in central Guyana (Fig. I). we record 10 additional species of bats for Iwokrama Forest encompasses 3,600 krn2 of primary the country and provide comments on taxon- mixed lowland tropical rainforest set aside by the government of Guyana in 1990 under the auspices of omy, distribution, measurements, and repro- the Commonwealth Secretariat for sustainable man- ductive data. This report is based primarily agement and conservation of biodiversity (Hawkes and 180 B. K. Lim, M. D. Engstrom, R. M. Timm, R. P. Anderson, and L. C. Watson forest with a clearing and road in the vicinity. Collec- tions were made on 29 March and 12 April 1997. Atlantic Before the access road was constructed and Ocean Iwokrama Forest was established, collections were made on 4,5, 10, and 11 October 1990,30 km NE of Surama in mixed lowland forest in what is now the south-central portion of Iwokrama Forest. From 17 to 31 July 1994 collections were made at Surama Saw- mill, 5 km SE of Surama adjacent to the southwestern extent of Iwokrama Forest in mixed lowland forest, which recently had been selectively logged. Additional records from previously unreported specimens at the ROM, which augment distributional t information for the species recorded herein, are also lwokrama presented (Fig. 1). These include collections made on 26 October and from 21 to 24 November 1996 at Gunn's Strip in the Upper Takutu-Upper Essequibo Region in southern Guyana. Gunn's Strip is a Wai- Wai village situated in seasonally flooded riparian forest bordering interior lowland shrub savanna. Other collections were made on the upper Essequibo River about 7 km S of Gunn's Strip from 15 to 20 November FIG. 1. Map of Guyana showing Iwokrama Forest and 1996. The habitat there was tall evergreen hill-land the collecting sites of the 10 new records of bat forest. Collections were made from 28 October to 6 species for the country reported in this paper: (I) November 1996 at Chodikar River, about 55 km SW Georgetown; (2) Bada Creek; (3) Pakatau Falls; (4) of Gunn's Strip near the border with Brazil in tall Clearwater Camp; (5) Iwokrama Field Station, evergreen non-flooded hill-land forest. Other records Kurupukari; (6) Three Mile Camp; (7) 30 km NE of were derived from specimens made by other collectors Surania; (8) Surama Sawmill; (9) Illia Wau River; (10) and are described in the species accounts. Gunn's Strip; (11) 7 km S of Gunn's Strip; and (12) The primary method used to capture bats was Chodikar River standard-weight (70-denier) mist nets of various sizes set in different microhabitats usually opened from Wall, 1993). One all-season access road, approxi- dusk to midnight. Bats flying below 3 m in the forest mately 70 km in length, bisects Iwokrama Forest from understorey were caught in regular-sized mist nets the northeast near Kurupukari on the Essequibo River (2.6x6.0 m or 2.6x12.0 m) typically set across flyways to the southwest near Surama, bordering the North such as streams and trails or near clearings and fruiting Rupununi Savannas. trees. Bats flying upwards to 20 m in the forest canopy The collecting sites (Fig. 1; see also Gazetteer) were caught with large-sized mist nets (9.1x30.5 m) within Iwokrama Forest included: (I) Pakatau Falls is set over roads or rivers within rainforest. Mist netting on the Siparuni River near the mouth of Pakatau Creek was supplemented with 4-bank harp traps usually set in the northwest in mixed, poorly drained forest near across narrow streams or trails, and shotguns (12 high hills dominated by Mora, Pentaclethra, and gauge and 0.410 calibre) with ammunition ranging Licania. Collections were made from 9 to 16 March from number 6 to 12 shot. Although the searching for 1997; (2) Three Mile Camp is in the northeast along roost sites was not an active part of our field protocol, the road approximately 5 km southwest of Kurupukari we checked potential roosts when encountered. in undulating terrain on well-drained brown sand with lowland forest dominated by Licania, Chlorocardium, Specimens and Measurements and Eschweilera. Collections were made from 18 to 28 March 1997; (3) Cleanvater Camp along the Burro Specimens were prepared as dried skins with Burro River approximately 25 km WNW of Kuru- skeletons or fixed in 10% formalin with storage in pukari is in the north in mixed lowland forest domi- 70% ethanol. All specimens had tissue samples (heart, nated by Chlorocardium, Eperua, and Eschweilera on kidney, spleen, liver) frozen initially in liquid nitrogen well-drained white sand. Collections were made from with later storage in an ultracold freezer (-80°C). 30 March to 11 April 1997; (4) Iwokrama Field Voucher specimens were deposited at the Angelo State Station is in the northeast on the Essequibo River Natural History Collection (ASNHC), Royal Ontario about 1 km N of Kurupukari in disturbed alluvial Museum (ROM), U.S. National Museum of Natural First records of 10 species of bats in Guyana 181 History (USNM), University of Guyana, Centre for the basisphenoid region) were recorded as described by Study of Biological Diversity (UGICSBD), and Genoways and Williams (1979), including greatest University of Kansas Natural History Museum (KU). length of skull, zygomatic breadth, mastoid breadth, Each species account includes a list of specimens postorbital breadth, length of maxillary toothrow examined (sample size in parentheses) followed by (C-M3), and breadth across upper molars (M3-M3; see Region in Guyana, specific locality, and museum Table 2). catalogue numbers for specimens examined. Details of reproductive condition included testes (T) length by width in mm for males. For females we report presence or absence of an embryo with crown-rump length (CR) if present and note whether the individual was lactat- Family Emballonuridae ing. Details of capture, such as microhabitat, date, and time were recorded for each species. External mea- Centronycteris maximiliani (Fischer, 1829) surements (in mm) and body mass (in g) were recorded in the field as described in Nagorsen and Peterson Specimens examined (3). -Potaro-Sipa- (1980) and presented in Table 1, including total runi; Cleanvater Camp (KU 156014); Paka- length, length of tail, length of hindfoot, length of ear from notch, length of tragus,'length of forearm, and tau Falls (ROM 107081, 107082). body mass. Cranial measurements (in mm) for adult Two adult females were netted together specimens (complete ossification of phalanges and about 10 m above the ground in the forest TABLE1. Range of six external measurements (in mm), including total length (TL), tail length (TAIL), hindfoot length (HFL), ear length (EAR), tragus length (TRAGUS), forearm length (FAL), and body mass (MASS, in g) of 10 new country records of bats for Guyana. Sample sizes differing from those reported under n are given in parentheses after the measurement or mass Species n TL TAIL HFL EAR TRAGUS FAL MASS Emballonuridae Centronycteris maximiliani 3 9 9 56-63(2) 17-23 6-7 14-17 4-6 44-46 5-6 Diclidurus albus 9 8 22 12 D. ingens 106 23 12 D. isabellus 83-92 15-24 12-14 86 20 11 Peropteryx leucoptera 56 5 8 59-61 9-1 1 7-9 Phyllostomidae Micronycteris brosseti 5 1 12 10 5 6 11 10 M. microtis 59 12 9 53-60 13-15 9-10 Tonatia carrikeri 77-95 9-16 15-17 74-88 15 16-17 Vespertilionidae Lasiurus atratus 115 5 2 10 Myotis riparius 78-85 35-39 7-10 80-83 33-38 8-9 182 B.