Resource availability and territorial behavior in Ruby-throated Hummingbirds (Archilochus colubris) at UMBS

Abstract

The goal of this study was to determine if Ruby-throated Hummingbirds (Archilochus colubris) exhibited territorial behaviors in relation to varied degrees of nectar availability. In order to examine this territorial behavior, we worked with students in the ornithology class to set-up 6 feeding sites at the edge of a field and woods at the University of Michigan Biological Station (UMBS) in Pellston, Michigan. Feeders at the sites were used to mimic low, intermediate, and high resource availability. Our group predicted that males would exhibit more territorial behavior than females at the sites with higher resource abundance. We also expected the most interactions to occur among males. We observed and recorded the territorial behavior of chasing at the feeding sites 3 times a day for hour-long periods for 4 days. Our results showed that the highest number of chasing behavior occurred at the single-feeder stations amongst females. We observed relatively low numbers of chasing between males. Furthermore, we observed that males preferred visiting sites with more feeders whereas females did not exhibit a clear preference of feeder abundance. Further studies on hummingbird territorial behavior would be beneficial to clarify whether chasing amongst females is common.