Competition Between Hermit Hummingbirds Phaethorninae and Insects for Nectar in a Costa Rican Rain Forest

Summary Hummingbirds in the tropical rainforests of southwestern Costa Rica face intense competition from stingless bees Trigona that steal nectar from hummingbird flowers. Here we document both interference and exploitative competition between bees and hummingbirds at scarlet, hummingbird pollinated flowers of Passiflora vitifolia . Aggressive stingless bees prevented Long‐tailed Hermit Hummingbirds Phaethornis superciliosus from feeding at nearly one‐third of the passion flowers approached. In exclusion experiments, bees and hummingbirds each removed most of the nectar from treated flowers. Experimental exclusion of bees also increased hummingbird use of both natural and artificial flowers.