Description of Echolocation Call Parameters for Urban Bats in Vietnam as a Step Towards a More Integrated Acoustic Monitoring of Urban Wildlife in Southeast Asia

Abstract

This study is the first step towards more systematic monitoring of urban bat fauna in Vietnam and other Southeast Asian countries by collecting bat echolocation call parameters in Ho Chi Minh and Tra Vinh cities. We captured urban bats and then recorded echolocation calls after releasing in a tent. Additional bat’s echolocation calls from the free-flying bats were recorded at the site where we captured bat. We used the obtained echolocation call parameters for a discriminant function analysis to test the accuracy of classifying these species based on their echolocation call parameters. Data from this pilot work revealed a low level of diversity for the studied bat assemblages. Additionally, the discriminant function analysis successfully classified bats to four bat species with an accuracy of >87.4%. On average, species assignments were correct for all calls from Taphozous melanopogon (100% success rate), for 70% of calls from Pipistrellus javanicus, for 80.8% of calls from Myotis hasseltii and 67.3% of calls from Scotophilus kuhlii. Our study comprises the first quantitative description of echolocation call parameters for urban bats of Vietnam. The success in classifying urban bats based on their echolocation call parameters provides a promising baseline for monitoring the effect of urbanization on bat assemblages in Vietnam and potentially also other Southeast Asian countries.

Echolocation call characterization of insectivorous bats from caves and karst areas in southern Luzon Island, Philippines

“…The fundamental harmonic of its call is often weakly discerned while the first harmonic is the strongest component (Heller 1989). Calls of this species recorded in this study is well within the range of call measurements recorded from other localities such as in Luzon Island (Amberong et al 2021), Malaysia (Heller 1989;Kruskop & Borisenko 2013), Vietnam (Pham et al 2021), and Thailand (Thong et al 2018).…”

Diversity Aspects in Bats: Genetics, Morphology, Community Structure

“…At the same time, the attention of researchers, especially in the tropics, has been mainly focused on the inhabitants of primary natural habitats, while urban fauna remain "behind the scenes". An article by Pham et al [4] partially fills this gap. However, since the direct capture of bats in urban environments is highly problematic, the authors resorted to modern acoustic monitoring methods by collecting bat echolocation call parameters in Ho Chi Minh and Tra Vinh cities.…”