Resource defense and territorial behavior in Ruby-throated Hummingbirds (Archilochus colubris).

Abstract

The purpose of this study was to record the behavior of polygynous ruby-throated hummingbirds (Archilochus colubris) along the shoreline of Douglas Lake in Pellston, Michigan. Eight artificial feeding sites were created, and four of the feeding sites contained three times more feeders than the other four. Territorial behaviors of vocalization, chasing, and guarding were recorded for both sexes at each of the eight sites, four times a day, for three days. Our main hypothesis was that male ruby-throated hummingbird vocalization and chasing would occur more frequently at triple-feeder sites than at single-feeder sites. With this in mind, we also tested to see whether female territorial behaviors would occur at single-feeder sites more frequently than triple-feeder sites. Our data showed significant evidence that males exhibit more territorial behaviors at the triple-feeder sites and females exhibit more territorial behaviors at the single-feeder sites. This evidence suggests that male hummingbirds base their territory selection on the amount of resources available. In addition, more female behavior at the single-feeder sites suggests that they can hold territories, too, but are unable to compete with the territorial males.