Supplementary material from "Multimodal duetting in katydids under bat predation risk: a winning strategy for both sexes"

Abstract: Duetting is a behaviour observed in some animal species, in which both males and females participate in signalling to find mates. It may have evolved as an adaptation to reduce the costs associated with mate-finding behaviours, such as predation risk. Duetting systems allow estimation of sex-specific predation risks of signalling and searching in the same species, giving insights into the selective forces acting on these behaviours. Using an acoustic-vibratory duetting katydid, Onomarchus uninotatus, and its bat predator, Megaderma spasma, we estimated the sex-specific predation costs of different mate-finding behaviours, such as walking, flying and signalling, by conducting experiments with untethered live katydids and bats. We found that acoustic-vibratory duetting benefits both the sexes as a low-risk mate-finding strategy. Data description: Behavioural experiments were done in an enclosure set-up with free-flying bats and katydids. Bat response to different mate-finding behaviours (treatments) of katydid males and females was recorded to estimate predation risk. The main datasheet named "all_treatments" includes bat ID, prey sex, treatments, and bat response. The treatments for male katydids were call, walk and flight and for females were tremulation (vibratory signalling), walk and flight phonotaxis. Bat response is denoted as "1" and "0" for approach and no approach, respectively, to the treatments. However, multiple trials were conducted for flights, and if the bat approached at least once, it was considered as an approach. The datasheet named "all_flight_trials" includes bat responses to all flight trials. Analysis: R Statistical Software (v4.1.2; R Core Team 2021) was used to analyze the data. 95% bootstrap confidence intervals were obtained around the mean proportions of bat approaches to each treatment, with 10,000 replicates using bat IDs. The R script can be found in the file "code_bootstrapped_CI".