DOI: 10.5061/dryad.nzs7h44sx
title: Effects of sexual dimorphism on pollinator behaviour in a dioecious species

description: Floral traits often display sexual dimorphism in insect-pollinated
 dioecious plant species, with male individuals typically being showier
 than females. While this strategy is theorized to be optimal when
 pollinators are abundant, it might represent a risk when they become
 scarce, because the disproportionately high number of visits on the most
 attractive sex, males, might preclude efficient pollen transfer from males
 to females. Here, the effect of sexual dimorphism on pollination
 efficiency was assessed in experimental arrays of dioecious Silene dioica
 that were exposed to one frequent visitor of the species, Bombus
 terrestris, and that differed in the magnitude of sexual dimorphism for
 either flower number or flower size. We measured the number of visits on
 female plants, on female flowers and on the number of female flowers
 visited after a male flower, as well as the number of pollen grains
 deposited per stigma.
description: Column names and contents of the 3 sub-datasets are described
 below -&gt; DataSilene_Plants (one line = one
 plant) Nsession    Name of the experimental session (3
 treatments * 8 replicas = 24 sessions, named A to X)                  
  <br> Date    Day the session was performed                  
  <br> Hive    Hive identity                    <br> sex  
  Plant sex (F : female, M : male)                    <br> Dim    Are
 plants sexually dimorphic for flower number or flower size in the session
 ? (Dim : Yes, NoDim : No)                    <br> DimNumber    Are
 plants sexually dimorphic for flower number in the session ? (Dim : Yes,
 NoDim : No)                    <br> DimSize    Are plants sexually
 dimorphic for flower size in the session ? (Dim : Yes, NoDim : No)      
              <br> Ttt    Treatment (Number : number dimorphism, Size
 : size dimorphism, Control : no dimorphism)                    <br>
 ID    Plant identity                    <br> nflo    Flower number
 at the time of the experiment                    <br> wflo1    Width
 of flower number 1 (mm)                    <br> wflo2    Width of
 flower number 2 (mm)                    <br> wflo3    Width of
 flower number 3 (mm)                    <br> wflo4    Width of
 flower number 4 (mm)                    <br> wflo5    Width of
 flower number 5 (mm)                    <br> meansizeind    Mean
 flower width                    <br> VisitPerPlant    Number of
 bumblebee visits per plant                    <br> VisitPerFlower  
  Estimate of the number of bumblebee visits per flower (VisitPerPlant /
 nflo) -&gt; DataSilene_Bumblebees (one line = one
 sequence of ten visits by a bumblebee)                        
 Nsession    Name of the experimental session (3 treatments * 8
 replicas = 24 sessions, named A to X)                    <br> Date  
  Day the session was performed                    <br> Hive    Hive
 identity                    <br> Dim    Are plants sexually
 dimorphic for flower number or flower size in the session ? (Dim : Yes,
 NoDim : No)                    <br> DimNumber    Are plants sexually
 dimorphic for flower number in the session ? (Dim : Yes, NoDim : No)      
              <br> DimSize    Are plants sexually dimorphic for
 flower size in the session ? (Dim : Yes, NoDim : No)                  
  <br> Ttt    Treatment (Number : number dimorphism, Size : size
 dimorphism, Control : no dimorphism)                    <br>
 nflosession    Total number of flowers available in the session (male +
 female)                    <br> nfloFsession    Total number of
 female flowers available in the session                    <br>
 Order    Flying order  (order in which bumblebees exited the hive)      
              <br> S1    Sex of visited flower number 1              
      <br> S2    Sex of visited flower number 2                  
  <br> S3    Sex of visited flower number 3                  
  <br> S4    Sex of visited flower number 4                  
  <br> S5    Sex of visited flower number 5                  
  <br> S6    Sex of visited flower number 6                  
  <br> S7    Sex of visited flower number 7                  
  <br> S8    Sex of visited flower number 8                  
  <br> S9    Sex of visited flower number 9                  
  <br> S10    Sex of visited flower number 10                  
  <br> NbTotInd    Number of visited plants                  
  <br> NbFF    Number of visited female flowers                  
  <br> NbPF    Number of visited female plants                  
  <br> NbFM    Number of visited male flowers                  
  <br> NbPM    Number of visited male plants                  
  <br> ShiftFM    Number of shifts from a female to a male flower  
                  <br> ShiftMF    Number of shifts from a male to a
 female flower                    <br> NoShift    Number of
 transitions between flowers that do not involve a change in visited sex   
                  <br> NbFpostM    Number of female flowers visited
 after the insect had visited at least one male flower (estimate of the
 number of potentially pollinating visits)                    <br>
 NbFbef    Number of female flowers visited before any male in the
 sequence                     -&gt;
 DataSilene_Pollen (one line = one female plant)
 Nsession    Name of the experimental session (3 treatments * 8
 replicas = 24 sessions, named A to X)                    <br> Date  
  Day the session was performed                    <br> Hive    Hive
 identity                    <br> Dim    Are plants sexually
 dimorphic for flower number or flower size in the session ? (Dim : Yes,
 NoDim : No)                    <br> DimNumber    Are plants sexually
 dimorphic for flower number in the session ? (Dim : Yes, NoDim : No)      
              <br> DimSize    Are plants sexually dimorphic for
 flower size in the session ? (Dim : Yes, NoDim : No)                  
  <br> Ttt    Treatment (Number : number dimorphism, Size : size
 dimorphism, Control : no dimorphism)<br> ID    Plant
 identity<br> nflo    Flower number at the time of the
 experiment<br> VisitPerPlant    Number of bumblebee visits per
 plant<br> VisitPerFlower    Estimate of the number of bumblebee
 visits per flower (VisitPerPlant / nflo)<br> MeanPollen    Mean
 number of pollen grains deposited per stigma