DOI: 10.5061/dryad.gf1vhhmzq
title: Data from: The perceptual effects of signal components: Black sword margins are crucial for signal size discrimination in green swordtails Xiphophorus hellerii

description: The signals that mediate mate choice can be complex, comprising multiple
 components, and understanding how complex signals evolve under sexual
 selection has been the focus of much study. However, open questions still
 remain about the role of the female’s sensory and perceptual processes in
 shaping the evolution of complex signals. Male green swordtails
 Xiphophorus hellerii have an elongated caudal fin that comprises color,
 length, and a black melanic margin; females prefer males with larger
 bodies, longer swords, and complete black sword margins. Here, we used a
 two-choice assay to quantify female preferences for animations of courting
 males of different sizes with or without sword margin coloration, and
 found that, when a black melanic margin was present, females exhibited
 preferences for larger males. However, when the margin was absent, females
 did not show size-based mate preference, though females spent equal time
 assessing males in both treatments.  Our results suggest the
 presence/absence of the black sword margin is an important predictor of
 female preference, specifically a female’s ability to discriminate between
 potential mates of different sizes, pointing to a novel size
 discrimination function of black margins in animal signals, which in many
 species involve patterns or structures with dark edges.
description: A two-choice behavioral paradigm was used to assess a female’s
 preference when shown animations of two courting males that differed in
 size, and which did or did not have black coloration along the top and
 bottom margins of the sword fin (hereafter “black margin”). Stimuli were
 created using a digital photograph of a male swordtail who was placed on a
 plain gray background and whose swimming motions were animated in
 Powerpoint. For details, see manuscript. 
description: # The perceptual effects of signal components: Black sword margins are
 crucial for signal size discrimination in green swordtails Xiphophorus
 hellerii
 [https://doi.org/10.5061/dryad.gf1vhhmzq](https://doi.org/10.5061/dryad.gf1vhhmzq) ## Description of the data and file structure ### Files and variables #### File: Body\_size\_two\_choice\_data\_stripe\_and\_no\_stripe.csv **Description: This** file contains data from each behavioral trial conducted in this study; note that each trial comprises two rows of data, since for each trial, the fish was exposed to two animated stimuli. Thus, in a pair of rows, one row shows data for responses to one stimulus, and the other row shows data for the response to the other stimulus. NOTE: Empty cells in this datasheet indicate fish and trials for which--due to stress responses--there were no data; thus, empty cells indicate instances where certain fish did not have analyzable data for certain stimulus comparisons, as discussed in the main text. ##### Variables -Fish_ID: A unique fish identifier for each individual, given based on the color of elastomer tags -Date: the date on which the trial was run -Comp_Num: Comparison number; for example, the first pair of stimuli shown to the fish was Comparison 1, the second pair was Comparison 2, etc. -Treatment: “Stripe” (black margin on the sword present) or No_Stripe (black margin on the sword absent) -Stimulus: a number indicating which stimulus is referred to; the original stimulus is 100 (100% size), and the numbers indicate how much the stimulus was scaled up or down to achieve a stimulus of a given area -Area_large: For the comparison in that row of data, the area (in mm squared) of the larger stimulus -Area_small: For the comparison in that row of data, the area (in mm squared) of the smaller stimulus -Stimulus_Side: whether the stimulus in that row was shown on the lefthand or righthand size of the tank -Time_with_Stim: The number of seconds spent with that stimulus in that trial -Latency_to_Visit: The amount of time that passed, in seconds, before the first visit to a given stimulus -Visits_to_Stim: The number of visits made to that stimulus in the 3-minute trial ## Code/software Caves and Kelley_R Code.Rmd: -An R Markdown file which runs all of the analyses and creates all of the figures in the manuscript and extended data.