Figure 4. A Preference for different Clarkia pollen
based on samples taken from foraging bees. Preference was calculated as
the difference between frequency of a Clarkia species blooming in
the community and frequency it was represented in bees’ pollen balls.
Mean preference is plotted with a 95% confidence interval, and was
estimated using quantitative amplicon sequencing. Estimates of
preference did not significantly differ between quantitation methods
(not shown). B Bar plots showing pollinator constancy. The
far-left bar shows what we would expect if bees are inconstant: for
example, the 34 bees caught in communities with four co-floweringClarkia species (black section of the far-left bar) should have
four Clarkia species in their pollen balls. We estimated the
number of Clarkia species found on bees in four ways:
quantitative amplicon sequencing (qAMPseq), and relative read abundance
(RRA) at different sample proportion cutoffs. Bees carried fewer species
in their pollen balls than were flowering in their correspondingClarkia communities. The far-right bar is relative read abundance
with no sample proportion cutoff; with this quantitation method, all
samples contained all four species.