Antagonistic effects of predator colour morph abundance and saliency on prey anti-predator responses
Data files
Jun 26, 2025 version files 21.44 KB
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Data_Abundance.txt
5.81 KB
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Data_BehaviouralResponses.txt
11.85 KB
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README.md
3.78 KB
Abstract
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.
Dataset DOI: 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)