DOI: 10.5061/dryad.b2rbnzsst
title: Honest signalling in predator-prey interactions: testing the resource allocation hypothesis

description: Warning signals are honest if they reliably deliver information about prey
 unprofitability to predators. One potential mechanism that may create and
 maintain a positive relationship between the strength of signals and
 defence is the resource allocation between these costly traits. Here, we
 test this hypothesis using the wood tiger moth Arctia plantaginis, whose
 females’ red hindwings are a warning signal to predators but show
 considerable variation in colouration within populations. These moths also
 produce a defensive chemical that is known to influence avian predator
 attack risk. Using dietary manipulations, image and chemical analyses, and
 experiments with ecologically relevant predators we demonstrate that
 protein availability during development can influence the strength of both
 the primary warning signal and the secondary defence. Our results show
 that females raised on a high-protein or ad libitum natural diet produced
 more distasteful defensive fluids than those raised on a low-protein diet
 or subjected to periodic food deprivation. While the patterning of the
 warning signal was unaffected by food deprivation, its efficacy was
 diminished in moths raised on a low-protein diet. However, this change was
 imperceptible to avian predators. Critically, resource availability
 influenced the relationship between signal strength and defence: moths on
 a high-protein diet displayed a positive correlation between warning
 signal strength and unpalatability, whereas this correlation was absent in
 moths raised on a natural diet. These findings show that resource
 availability can weaken the reliability of warning signals as an indicator
 of an individual’s defensive capabilities, highlighting the complex
 interplay between ecological conditions and the evolution of honest
 signalling.
description: # Honest signalling in predator-prey interactions: testing the resource
 allocation hypothesis This dataset includes the txt files: 1.
 **BirdVisionHonestyAlldata.txt** — Data on image analysis of wood tiger
 moth wings 2. **bird_response_female.txt** — Data of predator responses to
 female moths' thoracic fluids under different diet treatments 3.
 **LifeHistory_Honesty.txt** — Life-history data for moth individuals under
 different treatments. --- ## 1. BirdVisionHonestyAlldata.txt This file
 contains measurements from vision modelling and reflectance spectra for
 individual moths. Each row corresponds to a specific ROI (region of
 interest) from a moth wing. Key columns include: * Label: Unique label for
 each moth and ROI * ID: ID of individual moth * Treatment: Diet treatment
 of the moth (DH: natural diet ad libitum; DL: natural diet food deprived
 one day per week; NH: high protein diet; NL: low protein diet) * Family:
 Moth family * ROIs: Region of interest on the wing (e.g., f1, h1) *
 `lumMean`, `lumSD`: Mean and standard deviation of luminance * area: Area
 of the ROI in pixels * `maxPower`, `maxFreq`: Peak power and frequency of
 reflectance * `mwMean`, `mwSD`: Mean and SD for medium-wavelength cone
 stimulation * `lwMean`, `lwSD`: Mean and SD for long-wavelength cone
 stimulation * `dblMean`, `dblSD`: Mean and SD of double cone stimulation *
 `U`, `B`, `G`, `R`: Cone responses for UV, Blue, Green, and Red cones *
 `Lum`: Final luminance value --- ## 2. bird\_response\_female.txt This
 file includes predator response data (e.g., hesitation, approach time)
 from trials in which birds interacted with thoracic fluids of moths. **Key
 columns include:** * `birdid`: ID of the bird * `sex`: Sex of the bird *
 `age`: Age category of the bird (juvenile/adult) * `treatment`: Diet
 treatment of the moth (DH: natural diet ad libitum; DL: natural diet food
 deprived one day per week; NH: high protein diet; NL: low protein diet) *
 `colour`: Colour morph of the moth * `trial`: Trial number (1 to 4) *
 `tsee`: Time (s) when bird saw the bait * `tapp`: Time (s) when bird
 approached the bait * `tattack`: Time (s) when bird attacked the bait *
 `teat`: Time (s) when bird started eating the bait * `latattack`: Latency
 to attack * `lateat`: Latency to eat * `propeat`: Proportion of bait eaten
 * `pbw`: Beak wipe occurred (1/0) * `nbw`: Number of beak wipes * `pw`:
 Drinking occurred (1/0) * `nw`: Number of drinks * `psh`: stress-related
 behavior (0/1) * `tfinal`: Trial end time (s) * `tduration`: Trial
 duration (s) Missing values are marked as 'na' --- ## 3.
 LifeHistory\_Honesty.txt This file includes life-history trait data from
 individual moths exposed to different diet treatments. **Key columns
 include:** * `ID`: Unique ID of the moth * `Family`: Family identifier of
 the moth * `Individual_number`: Individual label within family *
 `treatment`: Diet treatment (e.g., DH, DL, NH, NL) * `pupa_weigh`: Weight
 of the pupae (mg) * `survival`: Binary indicator of survival (1 =
 survived, 0 = did not) * `development_time`: Days taken to develop *
 `growth_rate`: Relative growth rate * `sex`: Sex of the individual
 (typically "female") * `ok`: Developmental quality or condition
 (e.g., ok, bad, pupa, crumpled) * `N_volume`: Volume (µl) of thoracic
 fluid (chemical defence)