DOI: 10.5061/dryad.1b4p03d
title: Data from: A novel alarm signal in aquatic prey: Familiar minnows coordinate group defences against predators through chemical disturbance cues

description: Animal signalling systems outside the realm of human perception remain
 largely understudied. These systems consist of four main components: a
 signalling context, a voluntary signal, receiver responses and resulting
 fitness benefits to both the signaller and receiver(s). It is often most
 difficult to determine incidental cues from voluntary signals. One example
 is chemical disturbance cues released by aquatic prey during predator
 encounters that may serve to alert conspecifics of nearby risk and
 initiate tighter shoaling. We aimed to test whether disturbance cues are
 released incidentally (i.e. as a cue) or are produced voluntarily
 depending on a specific signalling context such as the audience
 surrounding the individual, and thus constitute a signal. We hypothesized
 that if receivers use disturbance cues to communicate risk among
 themselves, they would produce more (or more potent) disturbance cues when
 present in a group of conspecifics rather than when they are isolated
 (presence/absence of an audience) and use disturbance cues more when
 present alongside familiar rather than unfamiliar conspecifics (audience
 composition effect). We placed fathead minnows (Pimephales promelas) in
 groups with familiar fish, unfamiliar fish or as isolated individuals with
 no audience present, and then simulated a predator chase to evoke
 disturbance cues. We used bioassays with independent receivers to assess
 whether the disturbance cues produced differed depending on the
 signallers’ audience. We found evidence of voluntary signalling, as
 minnows responded to disturbance cues from groups of fish with tighter
 shoaling while disturbance cues from isolated minnows did not evoke a
 significant shoaling response (presence/absence audience effect).
 Receivers also increased shoaling, freezing and dashing more in response
 to disturbance cues from familiar groups compared to disturbance cues from
 unfamiliar groups or isolated minnows (audience composition effect).
 Together, these findings support our hypothesis that disturbance cues are
 used as an antipredator signal to initiate coordinated group defences
 among familiar conspecifics involving shoaling, freezing and dashing. This
 study represents the strongest evidence to date that chemicals released by
 aquatic prey upon disturbance by predators serve as voluntary signals
 rather than simply cues that prey have evolved to detect when assessing
 their risk of predation.
description: data_Bairos-Novak_et_al_2019_JAEMicrosoft Excel spreadsheet of data used in the analysis of the publication "A Novel Alarm Signal in Aquatic Prey: Familiar Minnows Coordinate Group Defenses Against Predators Through Chemical Disturbance Cues" (see 'metadata' sheet inside .xlsx workbook).data.xlsxscript_Bairos-Novak_et_al_2019_JAER script used in the analysis of the publication "A Novel Alarm Signal in Aquatic Prey: Familiar Minnows Coordinate Group Defenses Against Predators Through Chemical Disturbance Cues" (see comments throughout code for more information).analysis.R