The role of secondary pollinators in the evolution of complex colour signals in a bimodal pollination system
Data files
Nov 24, 2025 version files 17.12 MB
-
Background_spectra.csv
156.46 KB
-
Bootstrapping.R
10.38 KB
-
BothTrtmFinalUV.csv
21.10 KB
-
C._obliquus_paint_spectra.csv
360.76 KB
-
C._obliquus_spectral_data_Main_MS.csv
16.51 MB
-
Cyrtanthus_long_RvsPC.csv
5.07 KB
-
Cyrtanthus_long_UvsPC.csv
3.03 KB
-
Cyrtanthus_long_YvsPC.csv
6.15 KB
-
Cyrtanthus_obliquus_bee_paint_comparisons_Proc_Roy_Soc.R
9.16 KB
-
Cyrtanthus_obliquus_colour_analysis.R
19.95 KB
-
Cyrtanthus_obliquus_Preferences___Pollen_limitation.R
9.22 KB
-
Pollen_limitation_data.csv
6.55 KB
-
README.md
9.33 KB
Abstract
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.
Dataset DOI: 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