DOI: 10.5061/dryad.6v834
title: Data from: The price of looking sexy: visual ecology of a three level predator-prey system

description: Colour signals and colour vision play a pivotal role in intraspecific
 communication and predator-prey interactions. However, the costs of
 expressing conspicuous sexual signals at multiple trophic levels have been
 largely overlooked. Sexual signals can also experience character
 displacement in sympatric populations of closely-related species, leading
 to potential changes in conspicuousness. We here investigate a
 bird-damselfly-fruit fly predator-prey system, where two closely related
 damselfly species have conspicuous, sexually selected wing coloration. The
 damselflies can occur in sympatry and allopatry and reproductive character
 displacement in the coloration size has been previously reported. We
 quantify the damselfly wing reflectance from replicated sympatric and
 allopatric populations, and use receptor noise models to investigate the
 visual discriminability of the wing coloration for the bird, damselfly and
 fly vision systems, against natural backgrounds. We perform
 electroretinograms to study damselfly eye sensitivity. We also estimate
 damselfly predation risk in natural populations. We find that the
 chromatic component of wing coloration makes males highly discriminable to
 the predator, but not to the prey. However, female wing coloration is
 predominantly cryptic for the predator and prey, and interestingly, also
 for male damselflies. A female being cryptic to conspecifics likely
 reduces male harassment. The estimates of predation risk partially support
 the discriminability results. We also show that there is no difference in
 colour vision sensitivity between the two damselfly species and sexes, and
 no difference in wing coloration or its discriminability between sympatric
 and allopatric populations. Our results suggest that sexually selected
 traits can be antagonistically selected by predators and prey, and that
 this antagonistic selection can be sex-dependent: males are paying a large
 cost in terms of conspicuousness, while females remain mostly cryptic. Our
 study thus emphasizes the need for investigating visual communication at
 multi-trophic levels since the degree of colour discriminability can
 differ between predators, prey and the focal species.
description: Graded responses from
 the electroretinograms.This file contains the
 graded responses for each individual electroretinogram. The first column
 corresponds to the wavelength (lambda) and the remaining columns to the
 response (in mV). The results are organized by species (virgo/splendens),
 sex (female/male) and eye region (dorsal/ventral).ERGs.xlsxReflectance spectra from natural backgrounds.This file contains reflectance spectra for the backgrounds. The first column corresponds to wavelength (wl) and each of the remaining columns to individual backgrounds (bkg1 to bkg78, in percentage of reflectance).Backgrounds.csvReflectance spectra of damselfly wings.This compressed file contains the reflectance spectra data for each individual damselfly. The folders are organized by sex (male/female), then by population, and then by species (virgo/splendens). The sympatric populations are: Focks, Husby, Länna, Skytt, Stora and Valsk. The allopatric populations for C. virgo are Ekdal, Flenm, Läbyv, Nackb, Riala and Svana. The allopatric populations for C. splendens are Bergs, Gurre, Hällby, Orsun, Vatve and Vikst. Each individual file is named as follows: Population_sex (m for male/f for female) species (v for virgo/s for splendens)_individual number_repeated measurement. For example Hallb_fs_05_02 means that this individual was captured at Hallb population, it is the splendens female number 5, and this is the second repeated measurement.Reflectances damselflies.zip