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 BURTON K. LIM', MARK D. ENGSTROM~, ROBERT M. TIMM~, ROBERT P. ANDERSON~, and L. CYNTHIA WATSON~ 'Centrefor Biodiversity and Conservation Biology, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario M5S 2C6, Canada; E-mail: burtonl@ rom.on.ca 2NaturalHistory Museum and Department of Ecology & Evolutionary Biology, University of Kansas, Lawrence, Kansas 66045-2454, USA 3Centre for 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 The mammalian fauna of Guyana is poorly documented in comparison with neighbouring countries in northern South America. Most of its species and their distri- butions are inferred (e.g., Eisenberg, 1989) from mammals reported in Venezuela (e.g ., Handley, 1976) and Suriname (e.g., Husson, 1978). Two recent publications (Parker et al., 1993; Smith and Kerry, 1996) reported on separate, small single-site collections from Guyana and indicate a renewed interest in the diversity of Guyanese mammals. Herein, we record 10 additional species of bats for the country and provide comments on taxon- omy, distribution, measurements, and repro- ductive data. This report is based primarily on the first of two field trips that constituted the mammal portion of the faunal survey for Iwokrama Forest coordinated through The Academy of Natural Sciences of Philadel- phia. Records from previously unreported specimens at the Royal Ontario Museum are also presented to augment distributional data. MATERIALS AND METHODS Study Sites Fieldwork was conducted primarily from 9 March to 12 April 1997 in the Iwokrama International Rain Forest Programme site in central Guyana (Fig. I). Iwokrama Forest encompasses 3,600 krn2 of primary mixed lowland tropical rainforest set aside by the government of Guyana in 1990 under the auspices of the Commonwealth Secretariat for sustainable man- agement and conservation of biodiversity (Hawkes and