DOI: 10.5061/dryad.g66247g
title: Data from: Boundary strength analysis: combining colour pattern geometry and coloured patch visual properties for use in predicting behaviour and fitness

description: 1.Colour patterns are used by many species to make decisions that
 ultimately affect their Darwinian fitness. Colour patterns consist of a
 mosaic of patches that differ in geometry and visual properties. Although
 traditionally pattern geometry and colour patch visual properties are
 analysed separately, these components are likely to work together as a
 functional unit. Despite this, the combined effect of patch visual
 properties, patch geometry, and the effects of the patch boundaries on
 animal visual systems, behaviour and fitness are relatively unexplored.
 2.Here we describe Boundary Strength Analysis (BSA), a novel way to
 combine the geometry of the edges (boundaries among the patch classes)
 with the receptor noise estimate (ΔS) of the intensity of the edges. The
 method is based upon known properties of vertebrate and invertebrate
 retinas. The mean and SD of ΔS (mΔS, sΔS) of a colour pattern can be
 obtained by weighting each edge class ΔS by its length, separately for
 chromatic and achromatic ΔS. This assumes those colour patterns, or parts
 of the patterns used in signalling, with larger mΔS and sΔS are more
 stimulating and hence more salient to the viewers. BSA can be used to
 examine both colour patterns and visual backgrounds. 3.BSA was successful
 in assessing the estimated conspicuousness of colour pattern variants in
 two species, guppies (Poecilia reticulata) and Gouldian finches (Erythrura
 gouldiae), both polymorphic for patch colour, luminance and geometry. 3D
 representations of the ΔS of patch edges (Fort Diagrams) of both species
 show that there is little or negative geometric correspondence between the
 chromatic and achromatic edges. All individuals have mΔS &gt; 1.5 for
 both chromatic and achromatic measures, indicating the high within‐pattern
 contrast expected for display signals. In contrast from what one would
 expect from sexual selection, all guppies have mΔS less than expected from
 random contacts between all pairs of patch colour/luminance classes. The
 correlation between chromatic and luminance ΔS is negative in both species
 but zero when correlating all possible kinds of edges between the colours
 of each species and morph indicating non‐random colour geometry. 4.The
 pattern difference between chromatic and achromatic edges in both species
 reveals the possibility that chromatic and achromatic edges could function
 differently. The smaller than random expected mΔS values in guppies
 suggests an anti‐predator function because guppies are never found without
 predators. Moreover, mΔS could vary with predation intensity within and
 among species. BSA can be applied to any colour pattern used in
 intraspecific and interspecific behaviour. Seven predictions and four
 questions about colour patterns are presented. 5.In species which are very
 convex, both chromatic and luminance mΔS change with viewing angle;
 geometry of signalling is as important as signal geometry.
description: WeightedMnSD function
 (MATLAB)This is the MATLAB
 function used to calculate the mean and SD deltaS weighted by boundary
 lengths. It can be used for any application in which you need to
 calculated weighted means and standard deviations.WeightedMnSD.mExample Boundary Strength Analysis of GuppiesThis is a series of data, MATLAB data files and MATLAB scripts used to make the guppy figures.Guppies.zipExample of Boundary Strength Analysis of Gouldian FinchesThis is a set of data, MATLAB data, and MATLAB scripts used to make the Gouldian Finch figures.GouldeanFinches.zip