Vol. 44 No. 1, 2005

Food Habits of Japanese Pipistrelles Pipistrellus abramus (Chiroptera: Vespertilionidae) in Northern Taiwan

Ya-Fu Lee^1,§,* and Ling-Ling Lee^2,§

1Department of Life Sciences and Institute of Biodiversity, National Cheng Kung University, Tainan 701, Taiwan
2Present address: Department of Life Sciences and Institute of Ecology and Evolutionary Biology, National Taiwan University, Tainan 106, Taiwan.

Ya-Fu Lee and Ling-Ling Lee (2005) The composition and seasonal variation 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 period 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 variations. 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.

Key words: Chiroptera, Bats, Pipistrellus abramus, Diet.

*Correspondence: §The two authors contributed equally to this study.