Long-term market surveys for live bats in trade in southwestern Indonesia.

Bats, the second most diverse mammalian Order, have great ecological and economical importance. Globally, a large proportion of bat species are threatened and the trade in bats, either dead or alive, imperils several species, and may pose health risk for those people handling them. In southwestern Indonesia, bats are sold at wildlife markets for traditional Asian medicines, especially as a treatment for asthma. After purchase, bats are slaughtered at the market location where they were sold. Between 2012 and 2025 we conducted 362 surveys in 34 animal markets on the islands of Sumatra, Java, Bali and Lombok, and counted live bats offered for sale. We recorded 2245 Pteropus bats and 1080 Cynopterus bats during 249 (68%) of the surveys, and most markets displayed between 5 and 10 bats with a maximum of 50 bats at any given time. More bats were displayed on weekends than on weekdays, and over the 14 years covered by our survey trade was stable. There was no observed seasonality in the number of bats for sale. Average asking prices were US$22.25 ± 1.15 for Pteropus bats and US$12.75 ± 4.19 for Cynopterus bats. Cities with lower purchasing power per capita offered more bats per million people than their more affluent counterparts. Indonesia is the largest Muslim country globally by population, and bats are considered haram (unfit for consumption). Consequently, we observed more bats in cities with larger Christian populations. We found no evidence that the harvest or collecting of bats in Indonesia is sustainable, but sufficient support that it is not. Given the illegality of the trade in live bats in Indonesia, as there are no legal harvest quotas for the species we observed in trade, we urge local and national authorities to more effectively enforce existing regulations concerning the sale of wildlife in the animal markets.