Testing the relative importance of local resources and landscape connectivity on Bombus impatiens (Hymenoptera, Apidae) colonies

Bee populations are decreasing worldwide. The underlying causes are
likely determined by factors at different scales. We tested the
relative importance of local resources and landscape connectivity on
64 bumblebee (Bombus impatiens) colonies in experimentally isolated
and connected habitat fragments. We used colony mass, no. of workers,
and no. of gynes to estimate colony performance. Landscape
connectivity did not significantly affect colony performance, but
local floral resources had a significantly positive effect, especially
in isolated fragments. These results suggest that bumblebee colonies
encountered sufficient floral resources within the local 1.4 ha
habitat fragments to support colony growth, making long-distance
foraging trips to neighboring fragments unnecessary. From a
conservation perspective, we suggest that efforts to improve colony
performance should prioritize boosting local floral resources over
manipulation of large-scale landscape features.