DOI: 10.5061/dryad.6m905qg8w
title: Data from: Glossiness disrupts predator localisation of moving prey

description: Movement is the “enemy of camouflage”, but most animals must move to find
 resources, such as mates, food and shelter. Therefore, strategies that
 disrupt predator localization or speed perception of moving prey can play
 a crucial role in prey survival.  Shiny or glossy appearances,
 which are characterised by having a high degree of specular (mirror-like)
 reflection of incident light, can disrupt predator hunting behaviours
 towards moving prey. Different mechanisms may explain this effect, but no
 study has attempted to identify the mechanisms that disrupt perception of
 moving glossy prey by non-human predators. Here, we present glossy green
 or grey targets to jumping spiders (Maratus griseus) and precisely
 document predator hunting behaviours using high speed videography. Jumping
 spiders were less precise at tracking glossy targets compared to control
 targets, suggesting glossiness may disrupt localisation of targets.
 Importantly for prey, jumping spider attack accuracy was substantially
 reduced towards glossy prey compared to control targets. These results
 were independent of underlying target colour, suggesting benefits of
 glossiness may be generalisable to differently coloured glossy animals.
 Our results indicate that glossiness creates an unpredictable target that
 is difficult for predators to localise, offering insights into the
 prevalence of dynamically coloured organisms in nature.
description: ## Data from: Glossiness disrupts predator localisation of moving prey
 #### Amanda M. Franklin, Molly R. Brown, Nikolas J. Willmott This files
 run the analyses in the above paper. All analysis files are paired with
 data files (indicated by similar naming convention). ### ANALYSIS FILES
 1_Specularity.R: extracts parameters to calculate specularity and then
 plots result 2_HemisphericalReflectance.R: averages and plots
 hemispherical reflectance data 3_TrackingAnalysis.R: analysis of tracking
 data 4_AttackAnalysis.R: analysis of attack data ### DATASETS
 **1_Specularity_spec.csv** Angular reflectance measurements at a series of
 predefined angles to quantify specularity Links with: 1_Specularity.R wl:
 wavelength (nanometers) Columns 2:148 - spectra data for each target
 treatment and the arena (ARN). Three replicate measurements for each
 angular measurement. TREATMENTS: GLS_GREN - glossy green GLS_GREY - glossy
 grey MAT_GREN - matte green MAT_GREY - matte grey BMT_GREN - background
 matching green BMT_GREY - background matching grey ANGULAR MEASUREMENT:
 -525: light source at -5 degrees, collector at 25 0020: light source at 0
 degrees, collector at 20 0515: light source at 5 degrees, collector at 15
 1010: light source at 10 degrees, collector at 10 1505: light source at 15
 degrees, collector at 5 2000: light source at 20 degrees, collector at 0
 25-5: light source at 25 degrees, collector at -5
 **2_HemisphericalReflectance_spec.csv** Hemispherical reflectance data for
 each treatment at the arena measured with an integrating sphere. Links
 with: 2_HemisphericalReflectance.R wl: wavelength (nanometers) Columns
 2:21 - spectra data for each target treatment and the arena (ARN). Three
 replicate measurements GLS_GREN - glossy green GLS_GREY - glossy grey
 MAT_GREN - matte green MAT_GREY - matte grey BMT_GREN - background
 matching green BMT_GREY - background matching grey
 **3_TrackingAnalysis_data.csv** Dataset describing spider position and
 target position immediately before a jump. x,y coordinates were recorded
 for the cephalothorax, abdomen and target for every frame in the video
 footage. These were used to calculate spider body orientation angle and
 target angular position relative to spider position. Links with
 3_TrackingAnalysis.R spiderID: identification number of the spider Gloss:
 Treatment variable explaining target glossiness: glossy, matte or
 background matching Colour: Treatment variable explaining target colour:
 grey or green Treatment: Variable combining both colour and gloss uqID:
 unique value for each spider for each treatment time: time within video,
 based on frame rate (i.e. increment of 1 is 1/1000th of a second because
 videos were filmed at 1000fps) head_xaxis: x-value for the cephalothorax
 head_yaxis: y-value for the cephalothorax body_xaxis: x-value for the
 abdomen body_yaxis: y-value for the abdomen target_xaxis: x-value for the
 target target_yaxis: y-value for the target slope_headbody: slope of a
 line intersecting the cephalothorax and abdomen points intercept_headbody:
 y-intercept of a line intersecting the cephalothorax and abdomen points
 slope_bodytarget: slope of a line intersecting the target and abdomen
 points intercept_bodytarget: y-intercept of a line intersecting the target
 and abdomen points angle_headbody: angle of the line intersecting the
 cephalothorax and abdomen points, from a horizontal line (degrees)
 angle_bodytarget: angle of the line intersecting the target and abdomen
 points, from a horizontal line (degrees) orientationangle_modelest: spider
 body orientation angle, estimated from the segmentation model (i.e.
 similar to angle_headbody) angularoffset: difference between spider
 orientation and position of the target in degrees. pointtype: if the
 angular measurement is at the start or end of a full body saccade
 **4_AttackAnalysis_data.csv** Behaviour data of spider attack behaviours
 during each trial. Data was recorded from high speed video footage. Links
 with 4_AttackAnalysis.R uqID: unique value for each spider for each
 treatmen spiderID: identification number of the spider Sex: sex of the
 spider (male or female) Trial: trial number for an individual spider
 Treatment: Variable combining both colour and gloss Colour: Treatment
 variable explaining target colour: grey or green Gloss: Treatment variable
 explaining target glossiness: glossy, matte or background matching
 LatencyJump: latency until the spider jumped at the target after entering
 arena (seconds) Jump.Dist: distance of jump from where spider began jump
 to target position (millimeters) Jump.Acc: distance between target
 location and spider location at end of jump (millimeters) Angle: angle
 between spider starting position, target and spider end position (degrees)
 Flex.Legs: whether the spider flexed its legs, indicated attempt to catch
 target (yes/no) CatchTarget: if the spider caught the target (yes/no)
 VerDist: vertical offset between spider position and target (millimeter)
 HoriDist: horizontal offset between spider position and target
 (millimeter) NA: Not applicable