Data from: Honey bees (Apis mellifera) modify plant-pollinator network structure, but do not alter wild species’ interactions

Honey bees (Apis mellifera) are widely used for honey production and crop
pollination, raising concern for wild pollinators, as honey bees
may compete with wild pollinators for floral resources. The first
sign of competition, before changes appear in wild pollinator
abundance or diversity, may be changes to wild pollinator interactions
with plants. Such changes for a community can be measured by
looking at changes to metrics of resource use overlap in
plant-pollinator interaction networks. Studies of honey bee
effects on plant-pollinator networks have usually not distinguished
whether honey bees alter wild pollinator interactions, or if they
merely alter total network structure by adding their own
interactions. To test this question, we experimentally introduced
honey bees to a Canadian grassland and measured
plant-pollinator interactions at varying distances from the
introduced hives. We found that honey bees increased the network
metrics of pollinator and plant functional complementarity
and decreased interaction evenness. However, in networks
constructed from just wild pollinator interactions, honey bee
abundance did not affect any of the metrics calculated. Thus, all
network structural changes to the full network (including
honey bee interactions) were due only to honey bee-plant
interactions, and not to honey bees causing changes in wild
pollinator-plant interactions. Given widespread and
increasing use of honey bees, it is important to establish
whether they affect wild pollinator communities. Our results
suggest that honey bees did not alter wild pollinator
foraging patterns in this system, even in a year that was drier
than the 20-year average.