Data from: The most effective pollinator principle applies to new invasive pollinators

G.L. Stebbins’ most effective pollinator principle states that when
pollinators are not limiting, plants are expected to specialize and adapt
to the more abundant and effective pollinator species available. In this
study, we quantify the effectiveness of bees, hummingbirds and hawkmoths
in a Chilean population of Erythranthe lutea (Phrymaceae), and examine
whether flower traits are subject to pollinator-mediated selection by the
most effective pollinator species during two consecutive years. Unlike
most species in the pollinator community, the visitation rate of the
recently arrived Bombus terrestris did not change substantially between
years, which together its high and stable pollen delivery to flower
stigmas made this species the most important in the pollinator assemblage
followed by the solitary bee Centris nigerrima. Flower traits were under
significant selection in the direction expected for short-tongue bees,
suggesting that E. lutea is in the initial steps of adaptation to the
highly effective exotic bumblebee. Our results confirm the applicability
of Stebbins' principle for new invasive pollinators, and stress their
importance in driving flower adaptation of native plant species, a
critical issue in the face of biotic exchange and homogenization.