DOI: 10.5061/dryad.7pvmcvf5g
title: Antagonistic effects of predator colour morph abundance and saliency on prey anti-predator responses

description: The colour polymorphisms of prey species are often maintained by apostatic
 selection. In particular, rarer morphs are thought to be at an advantage
 because attentional constraints result in predators forming search images,
 which are based on the most abundant prey morph. Predatory species can
 also be polymorphic and predator morph abundance may be maintained by a
 similar mechanism, given prey are also likely to form search images to
 ensure fast and appropriate anti-predatory responses. Alternatively, given
 that the predator polymorphism may be driven by other ecological factors
 (e.g., niche divergence or sexual selection), prey may instead be highly
 sensitive to the relative visual saliency of different predatory morphs,
 which in turn could impact predator morph abundance. Here, by combining
 empirical observations with a field experiment, we assessed how the
 relative abundance and saliency of different colour morphs of the
 predatory trumpetfish (Aulostomus maculatus) influenced the behavioural
 responses of a typical prey species, the bicolor damselfish (Stegastes
 partitus). We found that more abundant predator colour morphs were less
 salient in damselfish vision (relative to the background) than less
 abundant colour morphs. By presenting 3D models of each morph to
 damselfish, we found that they did not respond differently to more
 abundant or more salient morphs. Our results suggest that both the
 relative abundance and saliency of predator morphs could contribute
 towards the search images used by prey. Specifically, each morph could
 have relatively equal detectability if their abundance and saliency have
 antagonistic effects on search-image formation in prey.
description: # Antagonistic effects of predator colour morph abundance and saliency on
 prey anti-predator responses Dataset DOI:
 [10.5061/dryad.7pvmcvf5g](10.5061/dryad.7pvmcvf5g) Author list: Samuel R
 Matchette, Jeroen Schneider, Christian Drerup, Sandra Winters, Andrew N
 Radford and James E Herbert-Read ### Files and variables #### File:
 Data\_Abundance.txt **Description:** Abundance of each trumpetfish colour
 morph. To assess the overall abundance of each trumpetfish morph, we
 conducted a total of 158 linear transects across nine locations on reefs
 surrounding Curaçao, Netherland Antilles. Transects comprised a researcher
 on SCUBA swimming, continuously and at a steady rate, parallel with the
 reef crest for 15 minutes, roughly 5 m above the reef floor, recording via
 camera every individual trumpetfish within ~15 m either side of the
 transect bearing. The researcher filmed the transect continuously using
 two GoPro cameras fixed to a stereo camera rig. For every trumpetfish
 encountered, the researcher pointed the cameras towards the individual for
 ~2 s. The assessment of the colour of each trumpetfish encountered was
 accomplished in situ, relayed to the recording using a hand signal that
 was unique to each morph. ##### Variables * Day: Day number (1 - 401),
 spanning all survey dates * Transect_Number: Individual ID for each
 independent transect * Count: The number of trumpetfish (of that colour
 morph) encountered on a given transect * Morph: Number ID for each
 trumpetfish colour morph (3 levels: 1 = Brown, 2 = Blue, 3 = Yellow) ####
 File: Data\_BehaviouralResponses.txt **Description:** Behavioural
 responses of prey to each trumpetfish colour morph. We first created
 realistic 3D models of each trumpetfish colour morph, which, while on
 SCUBA, we presented to 48 bicolour damselfish colonies in a balanced
 randomised block design. Presentations involved hand-reeling each model
 between two tripods, passing over the colony halfway between the two. We
 filmed the behavioural responses of the damselfish to each model; these
 damselfish exhibit strong and characteristic behavioural responses to
 predators, such as inspection and avoidance behaviour. ##### Variables *
 Day: Day number (1 - 24) * Rep: Colony ID per day (2 levels), which
 cumulatively equates to 48 independent colonies (@ 2/day) * Treatment: The
 treatment model that was presented (3 levels: 1 = brown trumpetfish, 2 =
 blue trumpetfish, 3 = yellow trumpetfish) * Treatment_Order: The order of
 model presentation for a given colony (1-3) * Model ID: (1-3) Relates to
 the ID of the specific model used for a given treatment; three models were
 created for each treatment to avoid pseudoreplication * Location: The
 location of a given colony (4 levels: 1 = Playa Cas Abao, 2 = Kokomo, 3 =
 Piscadera Bay, 4 = Playa Porto Mari) * Colony_Depth: Depth (m) of each
 colony visited * Insp_Duration_f: The total amount of frames that at least
 one damselfish inspects a given treatment * Colony_Size: The maximum
 number of damselfish observed during the current treatment presentation *
 Insp_Total: The maximum number of damselfish observed inspecting at any
 one time * Avo_Total: The total number of individual avoidance responses
 observed for a given treatment * Insp_Distance: The distance (m) that the
 treatment model is from the colony when the first inspection response is
 observed * Avo_Distance: The distance (m) that the treatment model is from
 the colony when the first avoidance behaviour is observed *
 Insp_Duration_s: The total amount of time (s) that at least one damselfish
 inspects a given treatment (converted from Insp_Duration_f using an fps of
 29.97) * Max_Colony_Size: The maximum number of damselfish observed at any
 one time throughout a colony visit (across all three treatments)