The context dependency of pollinator interference: how environmental
conditions and species abundances impact floral visitation
Abstract
Pollinator foraging behavior determines floral visitation rates, an
important proxy to the strength of mutual- istic interactions. Although
there is evidence that pollinators modify their behavior in the presence
of other foragers, there are equivocal findings regarding whether or not
pollinators interfere with one another. We employ a functional-response
framework to analyse experimental data of times between floral visits
made by a focal pollinator and to estimate pollinator interference by
conspecifics and three other species. Additionally we develop and
compare models that allow different levels of resource availability and
the sub-lethal exposure to a neonicotinoid pesticide to modify how
pollinators forage alone and with co-foragers. We found that all
co-foragers interfere with a focal pollinator under at least one set of
abiotic conditions; for most species, interference was strongest at
higher levels of resource availability and with pesticide exposure.
Overall our results highlight that density-dependent responses are often
context dependent themselves.