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

Abstract

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 landuse 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 by Polionemobius taprobanensis and Gryllodes 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.

Phenotypic plasticity of acoustic traits in high-frequency lebinthine crickets (Orthoptera: Eneopterinae: Lebinthina)

“…Higher lability in the calling behaviours than in the call parameters may be attributed to a stronger influence of the immediate environment, such as eavesdropping by predators (Kolluru 1999 ; Nandi and Balakrishnan 2013 ), whereas call parameters may be more stereotyped owing to sexual selection and morphological constraint. Temporal call parameters are less repeatable than the frequency call parameter, which corroborates with previous studies on Lebinthus (Tan and Robillard 2021a ) as well as with other orthopterans (Kolluru 1999 ; Nityananda and Balakrishnan 2008 ; Deb et al 2012 ; Nandi and Balakrishnan 2013 ; Tan 2020 ). Call frequency is more constrained by the morphology of sound-producing organs than temporal parameters (Montealegre-Z et al 2011 ; Robillard et al 2013 ).…”

Acoustic signalling in Orthoptera

“…Bent et al, 2021;Gurule-Small and Tinghitella, 2019;Schmidt et al, 2014). Some species are able to adapt to anthropogenic noise to some extent at least (Gallego-Abenza et al, 2020;Lampe et al, 2014;Sathyan and Couldridge, 2021;Tan, 2020). Others may be relatively unaffected (e.g.…”

Highly diversified circadian rhythms in the calling activity of eneopterine crickets (Orthoptera: Grylloidea: Gryllidae) from Southeast Asia

“…Lastly, the divergence in the circadian cycle can also be attributed to interspecific competition for the acoustic niche, as observed in syntopic species of crickets from Southeast Asia and neotropical katydids (Greenfield, 1988;Tan & Kamaruddin, 2013Symes et al, 2020;Tan, 2020). For example, in Singapore C. admirabilis and N. malaya are syntopic (Fig.…”