DOI: 10.5061/dryad.sn02v6xd3
title: Traffic noise exposure impacts song production in wild male field crickets (Gryllus bimaculatus) under predator and intrasexual competition contexts

description: Animals are known to adjust their acoustic signals in the presence of
 anthropogenic noise. These changes may affect fitness by altering
 susceptibility to predators or changing signal efficiency in intra and
 intersexual interactions. Male field crickets, Gryllus bimaculatus, chirp
 to attract females, with chirp rate being an important success factor.
 Males reduce chirp rate when exposed to predators or traffic noise and
 increase it in response to male competitors. However, the combined effects
 of these pressures on signalling are unknown. This study examined whether
 antipredator responses are influenced by male-male competition and
 variation in traffic noise exposure. We used substrate-borne vibrations to
 simulate a predator approaching calling males and varied perceived
 male-male competition using playbacks. We found that responses to
 increased competition were affected by variation in traffic noise
 exposure, with males chirping faster as noise levels increased.
 Additionally, antipredator responses depended on an interaction between
 traffic noise and competition. Under high competition, males reduced chirp
 rate as traffic noise increased. Our results demonstrate that adjustments
 in signal production in response to noise pollution may negatively impact
 communication in both antipredator and competitive contexts, indicating
 more pervasive effects of anthropogenic noise than previously recognized.
description: # Context-dependent effects of traffic noise experience on song production
 in wild male field cricket, Gryllus bimaculatus
 [https://doi.org/10.5061/dryad.sn02v6xd3](https://doi.org/10.5061/dryad.sn02v6xd3) #### Dataset structure Two sheets can be found in the Excel file, named "Antipredator_responses" and "Latency_resume_calling". Both sheets are needed to examine the effect of environmental traffic noise, the presence of a neighbor calling within five meters, and whether the simulated predator was accompanied by a playedback competitor on the calling song of field cricket males.  Two .csv files (one for each Excel file tab) are also available under the respective names.  In "Antipredator responses", both pre- and post-threat song features can be found, i.e., ICI_baseline and Number_pulses_baseline, and ICI_response and Number_pulses_response, respectively.  Analyses on the latency to resume calling after threatening crickets are found in the Excel tab "Latency_resume_calling", where only two observations per tested male are found.  ###### Response variables -- description **ICI_baseline:** 10 inter-chirp intervals taken prior to experimentally interrupted song by simulating an approaching predator. **Number_pulses_baseline:** Number of pulses of the 10 first chirps before threatening. **ICI_response:** 10 inter-chirp intervals taken prior to experimentally interrupted song by simulating an approaching predator. **Number_pulses_response:** Number of pulses of the 10 chirps after threatening. **Latency_resume_sec:** Latency to resume chirping of threatened crickets. ###### Explanatory variables -- description **Environmental_traffic_noise_exposure:** Measured in dBs, represents the chronic exposure to traffic noise of each tested male at the location where it was located. This is calculated from the Distance_to_the_road in meters. Calculation is explained in Methods section. **Neighbor_presence5m:** (Yes / No), indicates whether the tested male has a calling neighbor within a distance of five meters. **Treatment:** (Threat / Threat_plus_played-back_male). It refers to the two simulated predator approaching that each tested cricket male was exposed during the study. In the "Threat_plus_played-back_male", a conspecific calling song was played back 30 seconds before the threat (see Experimental protocol section for more details). **Order_Treatment:** (first / second), refers to the order in which the two treatments were presented. We randomized it across tested males.  ###### Other variables -- description **Tested_male:** Tested male found calling at a certain distance from a highway. **Date:** format Day/Month/Year - 00/00/0000 **Time:** format Minute:Hour - 00:00 **Highway:** Name of the three highways in which the experiments were conducted. **Broadcasting_male:** Identity of the three males used for artificially increasing male-male competition during threating (Treatment: Threat_plus_played-back_male). **Measure_allocation:** It goes from 1 to 10 and represents the order of measurement taken in Raven Pro. **ICI_baseline_mean:** Calculated mean of the 10 ICI (Inter-chirp interval) measured before threatening **Number_pulses_baseline_mean:** Calculated mean of the pulses per chirp before threatening **ICI_baseline_mean_without_pback_male:** Calculated mean of the ICI during baseline and in the treatment *Threat* ## Code/Software The R script allows 1\) analyse the effect of the explanatory variables on "Latency_resume*sec"* 2\) examine the effect of male-male competition on chirp rate adjustments (ICI_baseline) 3\) calculate "**Delta_ICI**" = ICI_response - ICI_baseline, and examine the effect of the three-way interaction term composed by **Environmental_traffic_noise_exposure, Neighbor_presence5m** and **Treatment** on it.  Codes for variables transformation, predicted & raw data plotting as well as model comparison using likelihood ratio tests, are included in the R script.