Food Habits of Japanese Pipistrelles Pipistrellus abramus (Chiroptera: Vespertilionidae) in Northern Taiwan Ya-Fu Lee 1,3, * and Ling-Ling Lee 2,3 Department of Zoology, National Taiwan University, Taipei 106, Taiwan (Accepted October 17, 2004) Ya-Fu Lee and Ling-Ling Lee (2005) Food habits of Japanese pipistrelles Pipistrellus abramus (Chiroptera: Vespertilionidae) in northern Taiwan. Zoological Studies 44(1): 95-101. The composition and seasonal varia- tion in the diet of Japanese pipistrelles, Pipistrellus abramus, were studied by analyzing fecal samples collected from May 1988 to June 1990 in Chutung, northern Taiwan. The diet of these bats contained a variety of insects (12 orders) and spiders. The majority of pellets examined (86.3%) contained 3 to 6 prey items (mean = 4.2 ± 0.1). In decreasing order, beetles, dipterans, hymenopterans, caddisflies, moths, true bugs, and homopterans were the most frequently found (95.9% in total frequency of occurrence) and accounted for the highest volume percentages (96.7% in total) in the feces. The dietary heterogeneity index (DHI) of Japanese pipistrelles was 9.25, but this varied among monthly samples, and we found no apparent seasonal patterns. Both overall DHI values (9.43; 9.39) and the 95% confidence limits (8.17~11.05; 8.41~11.39) appeared to be greater in the peri- od of mid-summer to fall, and in the winter months, than in the period of Apr. to mid- summer (8.67; 7.52~10.18), respectively. The diets of the bats over the 3 seasonal periods were similar, with only minor varia- tions. Hymenopterans, moths, and caddisflies were more frequently taken, while true bugs and homopterans less frequently taken by bats after mid-July. Bats appeared to consume higher proportions of homopterans in the 1st than in the 3rd period, but higher proportions of true bugs in the 2nd than in either the 1st or 3rd periods; whereas higher proportions of hymenopterans were consistently taken in the 1st sampling year. http://www.sinica.edu.tw/zool/zoolstud/44.1/95.pdf Key words: Chiroptera, Bats, Pipistrellus abramus, Diet Zoological Studies 44(1): 95-101 (2005) Over the last several decades, many empiri- cal studies on food habits of bats have generated enormous amounts of data essential to our under- standing of foraging behavior and ecology of insect-eating bats (e.g., Rose 1967, Belwood and Fenton 1976, Fenton and Thomas 1980, Barclay 1985, Jones 1990, Rydell 1992, Churchill 1994, Shiel et al. 1998, Lee and McCracken 2002 2004). The majority of those studies, however, unavoid- ably focused on New World species, those of tem- perate Eurasia, and to a lesser extent, on African and Australian species. With few exceptions (e.g., Eckrich and Neuweiler 1988, Whitaker et al. 1999), we still know very little about the food habits of the majority of species of insectivorous bats in most parts of Asia. The Japanese pipistrelle, Pipistrellus abra- mus, is widely distributed in eastern and southern Asia from Siberia, Japan, Korea, eastern China, and Taiwan, to northern Vietnam, Burma, and India (Corbet and Hill 1992, Koopman 1993, Simmons 2005). These bats live in caves, tree cavities, and crevices, as well as in man-made structures such as houses and churches (Funakoshi and Uchida 1978). Some aspects of the population and reproductive biology of this species have been studied in Japan (Funakoshi and Uchida 1978, 1982, Uchida et al. 1988), Taiwan (Lu 1988, Ke 1995, Lee 1995), and China (Huang and Huang 1982), respectively. Their 95 *To whom correspondence and reprint requests should be addressed: 1 Department of Life Sciences and Institute of Biodiversity, National Cheng Kung University, Tainan 701, Taiwan. Tel: 886-6- 2757575 ext. 65524. Fax: 886-6-2742583. E-mail: yafulee@mail.ncku.edu.tw. 2 Present address: Department of Life Sciences and Institute of Ecology and Evolutionary Biology, National Taiwan University, Tainan 106, Taiwan. 3 The two authors contributed equally to this study.