Data from: Bumblebee flower constancy and pollen diversity over time

Bees often focus their foraging effort on a few or even a single flower
species, even if other equally rewarding flower species are present.
Although this phenomenon – called flower constancy – has been widely
documented during single foraging trips, it is largely unknown if the
behavior persists over longer time periods, especially under field
conditions with large spatial and temporal variation of resources. We
investigated the pollen diet of individuals from nine different Bombus
terrestris colonies up to six weeks, placed at either 0, 300 or 1000 m
from nearest autumn sown oilseed rape. Adjacency to oilseed rape affected
constancy, with a higher flower constancy in colonies far from fields.
Overall, 23 % of the pollen foraging trips were flower constant, and the
fraction of constant pollen loads did not change over time, although
repeatedly sampled individuals that were flower constant once often showed
different preferences at other sampling occasions, and the similarity
between pollen loads collected by the same individuals dropped over time.
This suggests that flower constancy and other learnt foraging strategies
likely change in response to shifting floral resources. How rapidly it
changes in response to changing resources, and if this differs between
species as well as within species depending on e.g. size, should be the
focus of future research. The average diversity of pollen from single
foraging trips was around 3 pollen types, and we found indications of
resource partitioning within the colonies resulting in higher colony-level
pollen diversity. Keywords: flower fidelity, Bombus, foraging, seasonal
shift, foraging preferences, Brassica napus.