DOI: 10.5061/dryad.4xgxd25cf
title: Data for: Size-dependent colouration balances conspicuous aposematism and camouflage

description: Colour is an important component of many different defensive strategies,
 but signal efficacy and detectability will also depend on the size of the
 coloured structures, and how pattern size interacts with the background.
 Consequently, size-dependent changes in colouration are common among many
 different species as juveniles and adults frequently use colour for
 different purposes in different environmental contexts. A widespread
 strategy in many species is switching from crypsis to conspicuous
 aposematic signalling as increasing body size can reduce the efficacy of
 camouflage, while other antipredator defences may strengthen. Curiously,
 despite being chemically defended, the gold-striped frog
 (&lt;i&gt;Lithodytes lineatus&lt;/i&gt;, Leptodactylidae)
 appears to do the opposite, with bright yellow stripes found in smaller
 individuals whereas larger frogs exhibit dull brown stripes. Here, we
 investigated whether size-dependent differences in colour support distinct
 defensive strategies. We first used visual modelling of potential
 predators to assess how colour contrast varied among frogs of different
 sizes. We found that contrast peaked in mid-sized individuals while the
 largest individuals had the least contrasting patterns. We then used two
 detection experiments with human participants to evaluate how colour and
 body size affected overall detectability. These experiments revealed that
 larger body sizes were easier to detect, but that the colours of smaller
 frogs were more detectable than those of larger frogs. Taken together our
 data support the hypothesis that the primary defensive strategy changes
 from conspicuous aposematism to camouflage with increasing size, implying
 size-dependent differences in the efficacy of defensive colouration. We
 discuss our data in relation to theories of size-dependent aposematism and
 evaluate the evidence for and against a possible size-dependent mimicry
 complex with sympatric poison frogs (Dendrobatidae). 
description: # Data for: Size-dependent colouration balances conspicuous aposematism
 and camouflage
 [https://doi.org/10.5061/dryad.4xgxd25cf](https://doi.org/10.5061/dryad.4xgxd25cf) James B. Barnett, Justin Yeager, Brendan L. McEwen, Isaac Kinley, Hannah M. Anderson, & Jennifer Guevara. For further information contact: James B. Barnett Email: barnettdata@gmail.com Web: www.jbbarnett.co.uk ## Description of the data and file structure ### SPECTROPHOTOMETRY DATA Data files: 01\_Spectrophotometry\_Frog.txt 02\_Spectrophotometry\_Background.txt Format: compressed (.zip) folders containing multiple tab-delimited text (.txt) files export format generated automatically by Ocean Optics Flame S-XR1-ES spectrophotometer (Ocean Optics Inc. USA) (appropriate for use with R package pavo 2 (Maia et al. 2019. Methods Ecol. Evol. 10:1097-1107, doi = {10.1111/2041-210X.13174})) File identification: Spectrophotometry\_Frog: file name prefixes refer to frog colour patches (Black = dorsum, Red = Spot, Yellow = Stripe) Spectrophotometry\_Background: file name prefixes refer to leaves of different colours (Beige, Black, Green, or Red) number following prefix refers to the leaf replicate (1-10) file name suffix refers to repeat measure for each leaf (1-3) \(e\.g\.\, "Red\-02\_Reflection\_003\.txt" = red leaf number 2\, 3rd measurement \| "Green\-10\_Reflection\_002\.txt" = green leaf number 10, 2nd measurement) ### VISUAL MODELLING DATA Data file: 03\_Internal\_contrast.txt Format: tab-delimited text Column identification: visual\_model: visual model used in the analysis (peafowl LMS) species: study species ("Lithodytes\_lineatus") frog\_number: unique number for each frog (1:30) SVL\_mm: snout-vent length (SVL) of each frog in millimetres colour\_contrast: colour comparison \(yellow = stripe vs dorsum \| red = spot vs dorsum\) dS: chromatic contrast dL: achromatic contrast ### DETECTION DATA Data files: 04\_Detection\_Exp01.txt 05\_Detection\_Exp02.txt Format: tab-delimited text Column identification: expt: experiment number (1 or 2) file: unique code for each human participant (randomly generated during anonymous trial) rt\_ms: reaction time in seconds (time taken to click on the frog) is\_hit: TRUE = correct click on frog, FALSE = frog not found cond\_1: frog age class (S = small, M = Medium, L = Large) cond\_2: colour condition treatment (A = dorsal only, B = dorsal & spots, C = dorsal & stripe, D = dorsal, spot, & stripe) cond\_3: frog size in millimetres \(exp 1 = 35 \| exp 2 = 20\, 35\, or 50\) trial\_idx: replicate number for each participant (1-48 trials) cond: combination of cond\_1 & cond\_2 ### RAW IMAGE FILES Data files: 06\_RawImages.zip (contains 30 image files, e.g., "01\_DSC\_1289.NEF") Format: .NEF Nikon RAW Image \*\* NB \*\* Codes within photographs (e.g., "LLI03") are from encounter surveys and includes frogs not sampled for colour analysis. Instead, 'frog\_number' as reported in the VISUAL MODELLING DATA (see above) is denoted in the file name (e.g., "03\_DSC\_1333.NEF").