Zoological Studies

Vol. 61, 2022

(update: 2022.6.22)

Population and Conservation Status of Pteropus dasymallus in Taiwan

Hui-Wen Wu1, Dau-Jye Lu1, Ching-Lung Lin2, Hsi-Chi Cheng3, Chung-Hao Juan4, Tsung-Jen Shen5, Hua-Ching Lin6, and Shiang-Fan Chen4,*
doi:-

1School of Forestry and Resource Conservation, National Taiwan University, Taipei 106319, Taiwan. E-mail: fiyana0267@gmail.com (Wu); djlu@ntu.edu.tw (Lu)
2Bat Association of Taiwan, Chiayi 606002, Taiwan. E-mail: linchinglung1@gmail.com (Lin)
3Division of Zoology, Endemic Species Research Institute, Nantou 552005, Taiwan. E-mail: chenghc@tesri.gov.tw (Cheng)
4Center for General Education, National Taipei University, New Taipei City 237303, Taiwan. *Correspondence: E-mail: schen@mail.ntpu.edu.tw (Chen).
E-mail: rparus25@gmail.com (Juan)
5Institute of Statistics and Department of Applied Mathematics, National Chung Hsing University, Taichung 402002, Taiwan. E-mail: tjshen@nchu.edu.tw (Shen)
6Forestry Bureau, Council of Agriculture, Taipei 100024, Taiwan. E-mail: franklin@forest.gov.tw (Lin)

Received 14 January 2022 / Accepted 4 May 2022
Communicated by Teng-Chiu Lin

Pteropus dasymallus is widely distributed on islands throughout the western edge of the Pacific Ocean. The Formosan flying fox, P. d. formosus, is an endemic subspecies in Taiwan found mainly on Lyudao; it was previously thought to have been extirpated. Since 2005, intensive surveys have been conducted to investigate the residency, population size and plant resource utilization of P. dasymallus in Taiwan. Interviews were carried out to investigate its former abundance and the causes of population decline. In Taiwan, P. dasymallus is in a state of ongoing oceanic dispersal and colonization and has considerably expanded its geographic range. In addition to remaining in its historic habitat on Lyudao, P. dasymallus has also established colonies on Gueishan Island and in Hualien on Taiwan’s main island in the past few decades; the population size is estimated to be 240 individuals, and this number is on the rise. Approximately three-quarters of the entire population (73.64%) was found on Gueishan Island. The sex ratio was strongly skewed toward males. A total of 40 plant species were recorded as providing the flying fox with food, roosts or perches. More agricultural and horticultural plant species were used by the flying fox in urban Hualien. According to the interviews, flying foxes were abundant on Lyudao, but their number dramatically declined from the 1970s to the mid-1980s, mainly due to commercial hunting. Maintaining a sufficient population size and genetic variability is fundamental to the long-term survival of the flying fox. Enforcing conservation laws, restoring habitat, controlling invasive species and improving public awareness are the main steps in the recovery and sustainability of the flying fox population.

Key words: Insular ecosystem, Interoceanic dispersal, Local extirpation, Pteropodidae, Ryukyu flying fox.

Citation: Wu HW, Lu DJ, Lin CL, Cheng HC, Juan CH, Shen TJ, Lin HC, Chen SF. 2022. Population and conservation status of Pteropus dasymallus in Taiwan. Zool Stud 61:34.