DOI: 10.5061/dryad.t4b8gtjdh
title: The role of secondary pollinators in the evolution of complex colour signals in a bimodal pollination system

description: Flower colour is recognized as a key trait influencing pollinator
 visitation and behaviour, evolved to match the sensory system of a
 particular pollinator group. However, some flowers combine colours
 associated with different pollinators, suggesting bimodal adaptation. The
 perennial herb Cyrtanthus obliquus produces red corollas with yellow tips
 and is pollinated by birds, but also by bees. To assess the role of the
 two pollinator categories in shaping selection on the bi-coloured
 corollas, we examined bee choices in arrays in which the colour signals of
 plants had been manipulated, and we quantified total as well as
 bird-mediated phenotypic selection on flower colour using both bird and
 bee visual models. Bees preferred flowers with a yellow signal over
 all-red flowers. The analysis of phenotypic selection indicated that both
 birds and bees influence net selection on flower colour, resulting in
 conflicting selection on the colour contrast between corolla and corolla
 tip. Our findings show that the optimal phenotype should depend on the
 relative importance of the two categories of pollinators in a given
 population, and are consistent with bimodal adaptation. This study fills
 an important gap by showing that secondary pollinators can contribute to
 selection on complex colour signals in angiosperm flowers.
description: # The role of secondary pollinators in the evolution of complex colour
 signals in a bimodal pollination system Dataset DOI:
 [10.5061/dryad.t4b8gtjdh](10.5061/dryad.t4b8gtjdh) ## Description of the
 data and file structure All data were collected in the field, in which
 selection was measured using preferences of painted treatments by bees,
 and phenotypic selection on floral characters using the Lande and Arnold
 approach. We also measured pollen limitation in combination with breeding
 system experiments on plants that were not used in the field selection
 experiments.  ### Files and variables #### File: BothTrtmFinalUV.csv
 **Description:** Dataset used to measure phenotypic selection #####
 Variables * ID: Identity of plant used to measure selection on floral
 traits, on open and caged treatments * Trtm: Treatment under which
 selection was measured, which was either "open" or
 "caged" * Guide: Proportion of yellow area relative to the red
 portion of the corolla * S_Guide: standardised guide - "with a mean
 of zero and a variance of one" - **repeated for all standardised
 measurements following from here on forward (i.e. headings with an S\_ in
 front of trait).** * Height: Height of inflorescence measured in
 millimeters * S_Height: standardized height - "with a mean of zero
 and a variance of one" * Flow: Number of flowers per
 inflorescence/individual * S_Flow: Standardized flower number -
 "" * Cor: Corolla length from top of ovary to where corolla
 flaresmeasured in millimeters * S_Cor: standardized corolla length *
 B_CorTip: Euclidean distance in hexagon units between the corolla tip
 (outer) and red part of the corolla in bee vision * S_B_CorTip:
 Standardized B_CorTip measurement * B_CorBack: Euclidean distance in
 hexagon units between the red part of the corolla and the background in
 bee vision * S_B_CorBack: standardized B_CorBack measurement * B_TipBack:
 Euclidean distance in hexagon units between the corolla tip (outer) and
 the background in bee vision * S_B_TipBack: Standardized distance of
 B_TipBack * BI_CorTip: Euclidean distance of units within the bird
 tetrahedral model between the corolla tip (outer) and red part of the
 corolla in bird vision * S_BI_CorTip: Standardized distance of BI_CorTip *
 BI_CorBack: Euclidean distance of units within the bird tetrahedral model
 between the red part of the corolla and the background in bird vision *
 S_BI_CorBack: standardized BI_CorBack measurement * BI_TipBack: Euclidean
 distance of units within the bird tetrahedral model between the corolla
 tip (outer) and the background in bird vision * S_BI_TipBack: Standardized
 distance of BI_TipBack * Fruits: Number of fruits set per individual *
 Seeds: Number of seeds set * RelFit: Relative fitnes calculated according
 to Lande and Arnold 1983: individual number of seeds produced divided by
 mean seed production #### File: Cyrtanthus_long_YvsPC.csv
 **Description:** Data set used to analyze preferences by bees between
 treatments painted completely yellow and painted the same colour as the
 naturally looking flower (painted control) ##### Variables * Year: Year
 experiment has been set-up * Date : Date experiment has been set-up *
 Species: Species of pollinator visiting flower * pollinator_ID: Identitity
 of individual pollinator visiting a series of treatments within the
 experimental array * Treatment: Either painted control or Yellow painted
 flower, highlighted as "PC" or "Y" * first_pref: First
 choice made by pollinator to a paired treatment within the array ####
 File: Cyrtanthus_long_UvsPC.csv **Description:** Data set used to analyze
 preferences by bees between treatments unpainted inflorescences that acts
 as a control, and those painted the same colour as the naturally looking
 flower (painted control) ##### Variables * Year: Year experiment has been
 set-up * Date : Date experiment has been set-up * Pollinator_species:
 Species of pollinator visiting flower * pollinator_ID: Identitity of
 individual pollinator visiting a series of treatments within the
 experimental array * Treatment: Either painted control or unpainted
 flower, highlighted as "PC" or "U" * first_pref: First
 choice made by pollinator to a paired treatment within the array * time:
 The time of day an individual pollinator entered the arena #### File:
 Cyrtanthus_long_RvsPC.csv **Description:** Data set used to analyze
 preferences by bees between treatments painted completely red and painted
 the same colour as the naturally looking flower (painted control)
 Variables * Year: Year experiment has been set-up * Date : Date experiment
 has been set-up * Species: Species of pollinator visiting flower *
 pollinator_ID: Identitity of individual pollinator visiting a series of
 treatments within the experimental array * Pair: pair number *
 Treatment: Either painted control or Yellow painted flower, highlighted as
 "PC" or "R" * first_pref: First choice made by
 pollinator to a paired treatment within the array * time: The time of day
 an individual pollinator entered the arena #### File:
 Pollen_limitation_data.csv **Description:** Dataset used to analyze
 pollen-limitation and breeding system data. Note that there is no data
 available under columns "code", and "Fruit_set" from
 row 26 onwards, hence we have filled the empty cells with an n/a for
 "not available". ##### Variables * Code: code of individual
 plant subject to a treatment * Treatment: Breeding system or
 pollen-limitation treatment ("Pollen_supplementation": hand
 pollination treatment or "open_treatment": open control
 treatment or "caged_treatment": chicken wire cage covered
 inflorescences) * Fruit_set: Number of fruits resulting from treatment *
 Seed_Set: Number of seeds resulting from treatment #### File:
 Background_spectra.csv **Description:** Raw spectral data from background
 components to generate an average background colour as input for the
 colour analysis ##### Variables * Wavelength: wavelength in nanometers *
 Veg_1: spectra of vegetative material 1 * Veg_2: spectra of vegetative
 material 2 * Veg_3: spectra of vegetative material 3 * Redish_rock:
 sandstone of reddish origin * light_rock: sandstone of light brown origin
 * average: spectra averaged across all background types per nanometer ####
 File: C._obliquus_spectral_data_Main_MS.csv **Description:** Raw spectral
 data from experimental plants used in selection analysis. This is the
 dataset containing the raw spectra used to conduct all main the colour
 analysis in the paper. ##### Variables * Wavelength: wavelength in
 nanometers * Columns B to AEO involve colour spectra taken at different
 parts of the plant for different invididuals associated with the
 phenotypic selection and colour analysis. Each column is labelled using
 the identity of plant individuals (e.g., MKO2) used in the selection
 analysis (see dataset BothTrtmFinalUV.xlsx), these individual codes are
 followed by a period in the header in which the header may then refer to
 the different traits measured for the individual in question (e.g.,
 MKO2.corolla). These are the following traits: * corolla: spectra taken
 from the red part of the corolla  * corolla_tip: spectra taken from the
 outer corolla tip * arrow: spectra taken from the inner corolla  where the
 tepals have folded together to make an arrow, this is red in colouration
 and virtually identical in colour to the red colour of the corolla *
 arrow_tip: spectra taken from the tip of the inner corolla * inside:
 spectra taken from the inside of the corolla * Column AEP labelled
 "Site1.background" refers to the averaged background colour *
 Columns AEQ to AEV refers to spectra taken from pollen of six different
 individuals, namely individuals 1 to 6 labelled "Ind1.pollen",
 "Ind2. pollen", etc, until individual six. #### File:
 C._obliquus_paint_spectra.csv **Description:** Raw spectral data from
 painted experimental plants used in choice experiments. ##### Variables *
 Wavelength: wavelength in nanometers Columns B to AG involve colour
 spectra taken from painted experimental plants in choice experiments. Each
 column is labelled using the identity of plant individuals (e.g., Ind1 or
 Ind8), these codes associated with each individual codes are followed by a
 period (e.g., Ind1. or Ind8.) in which the header then refers to the
 different painted floral parts measured for the individual in question
 (e.g., Ind1.redcor or Ind8.p_redtip). These are the following painted
 traits measured for each individual: * p_yelcor: spectra taken from the
 corolla painted yellow * p_yeltip: spectra taken from the outer tepal tip
 painted yellow * p_redcor: spectra taken from the corolla painted red *
 p_redtip: spectra taken from the outer tepal tip painted red # Information
 regarding R Documentation *
 **Cyrtanthus_obliquus_Preferences___Pollen_limitation.R**: R code used to
 analyze choice experiments by bees *
 **Cyrtanthus_obliquus_bee_paint_comparisons_Proc_Roy_Soc.R**: R code used
 to compare paints with different parts of natural flowers. These are
 controls used in the choice experiments. *
 **Cyrtanthus_obliquus_colour_analysis.R**: R code used to run colour
 analysis * **Bootstrapping.R**: R code used to run selection analysis ##
 Access information Other publicly accessible locations of the data: * NA
 Data was derived from the following sources: * NA