Soundscape of urban-tolerant crickets (Orthoptera: Gryllidae, Trigonidiidae) in a tropical Southeast Asia city, Singapore

摘要

Urbanisation impacts biodiversity tremendously, but a few species can still tolerate the harsh conditions of urban habitats. Studies regarding the impact of urbanisation on the soundscape and acoustic behaviours of sound-producing animals tend to overlook invertebrates, including the crickets. Almost nothing is known about their acoustic community in the urban environment, especially for Southeast Asia where rapid urbanisation is widespread. Grass verges in Singapore - characterised by complex mosaics of land-use types - were sampled as a microcosmic representation of the urban environment to address these questions: (i) What is the acoustic community of crickets in the urban environment? (ii) How do co-occurring species partition their calls? (iii) How do the call properties vary with environmental conditions and individuals? The calling songs of 10 species were recorded and they generally have distinct call signatures in both the time and frequency domains. The acoustic community was dominated byPolionemobius taprobanensisandGryllodes sigillatus. They also showed repeatabilites in their call properties with static properties being more repeatable than dynamic properties, but these call properties were not associated with environmental variables. The presence of these crickets is relevant for a biophilic city as they represent what most urban dwelling humans could frequently hear.