Data from: Higher iridescent-to-pigment optical effect in flowers facilitates learning, memory and generalization in foraging bumblebees
de Premorel, Géraud; Giurfa, Martin; Andraud, Christine; Gomez, Doris (2017), Data from: Higher iridescent-to-pigment optical effect in flowers facilitates learning, memory and generalization in foraging bumblebees, Dryad, Dataset, https://doi.org/10.5061/dryad.dj1b8
Iridescence—change of colour with changes in the angle of viewor of illumination— is widespread in the living world but its functions remain poorly understood. The presence of iridescence has been suggested in flowers where diffraction gratings generate iridescent colours. Such colours have been
suggested to serve plant–pollinator communication. Here we tested whether a higher iridescence relative to corolla pigmentation would facilitate discrimination, learning and retention of iridescent visual targets. We conditioned bumblebees (Bombus terrestris) to discriminate iridescent from non-iridescent artificial flowers and we varied iridescence detectability by varying target iridescent
relative to pigment optical effect. We show that bees rewarded on targets with higher iridescent relative to pigment effect required fewer choices to complete learning, showed faster generalization to novel targets exhibiting the same iridescence-to-pigment level and had better long-term memory retention. Along with optical measurements, behavioural results thus demonstrate that bees can learn iridescence-related cues as bonafide signals for flower
reward. They also suggest that floral advertising may be shaped by competition between iridescence and corolla pigmentation, a fact that has important evolutionary
implications for pollinators. Optical measurements narrow down the type of cues that bees may have used for learning. Beyond pollinator–plant communication, our experiments help understanding how receivers influence the evolution of iridescence signals generated by gratings.