Y-maze apparatus used for bumblebee behavioral tests.

<p>(a) Position of plexiglas plant chambers facing the arm ends. The chamber at the left contains no plant (control: empty pot with a wooden stick). The chamber at the left contains a <i>A</i>. <i>majus pseudomajus</i> plant with four open flowers. Connectors for plant scent collection are visible on the top of the chambers. (b) Fan causing an air flow from arm ends to the main channel. The hole above the fan was used to put the bees inside the Y-maze. The Y-maze neutral zone is red-shadowed.</p

Diversity statistics and results from selection tests for <i>Z. borbonicus</i> morphs.

<p>Π: nucleotide diversity. S: number of segregating sites. Significance levels:</p>*<p>p<0.05;</p>**<p>p<0.01.</p

Map showing <i>Z. borbonicus</i> sampling localities, and distribution of the four morphs on Réunion.

<p>Letters correspond to the different plumage morphs: A: Brown morph; B: Grey morph; C: Grey-headed brown morph; and D: Grey-headed brown-naped brown morph. For a more detailed description of pigmentation phenotypes, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050906#pone.0050906-Gill1" target="_blank">[17]</a>. Adapted from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050906#pone.0050906-Hubbard1" target="_blank">[18]</a>.</p

Analysis of time to first choice between <i>pseudomajus</i> and <i>striatum</i> plants.

<p>Anova-tests were carried out on Cox models modeling the probability to make a choice after a certain time, with bee experience and type of available plant signals as fixed effects, and hive and bee nested within hive as random factors. Each fixed effect was tested by controlling for the influence of all other fixed effects of equal or lower degree.</p

Flight cage used for bumblebee training procedure.

<p>Plants are of the subspecies <i>A</i>. <i>majus striatum</i> (yellow-flowered).</p

Localities and number of birds sampled on the islands of Réunion and Mauritius.

<p>Localities and number of birds sampled on the islands of Réunion and Mauritius.</p

Color loci of plants used in bumblebee behavioral tests, in the <i>B</i>. <i>terrestris</i> color perception space.

<p>Mean position ± SE (circle) per plant, on measures taken on the upper and lower petal on one to two flowers per plant. Magenta dots: <i>pseudomajus</i> plants; golden dots: <i>striatum</i> plants.</p

Analysis of bumblebee preference between the two <i>A</i>. <i>majus</i> subspecies, on the basis of their first choice.

<p>*** <i>P</i> < 0.001</p><p>** <i>P</i> < 0.01</p><p>* <i>P</i> < 0.05.</p><p>Log-likelihood ratio tests were performed on generalized linear mixed model modeling the probability to choose the <i>striatum</i> plant, with bee experience, type of available plant signals, and position of the <i>striatum</i> plant as fixed effects, and hive and bee nested within hive as random factors. Each fixed effect was tested by controlling for the influence of all other fixed effects of equal or lower degree.</p

Amino-acids variants observed at the <i>MC1R</i> locus in 51 <i>Z. borbonicus</i> individuals representing the four Réunion morphs and nine <i>Z. mauritianus</i> individuals.

<p>For each variant the corresponding nucleotide substitution is indicated, with its state (heterozygous or homozygous) in each morph and species studied here. Sequences were numbered in reference to the chicken genome (Genbank accession number: AY220305).</p

Description of the parental plant populations.

<p>Description of the parental plant populations.</p