Publication Date

Fall 2016

Program Name

Ecuador: Comparative Ecology and Conservation

Abstract

The study "Resource Quality and Defense: Feeding Behaviors and Female Territoriality in Two Species of Tropical Hummingbird" investigates the feeding behaviors and territoriality of hummingbirds at a flowering shrub of the Gesneriaceae family, Besleria solanoides. Four 1.25-hour observation periods were completed each day, rotating between four different observation sites. During each observation period, the sugar concentration of nectar and number of flowers on each bush was measured, and each time a hummingbird entered the area the following data was recorded: species, sex, time of arrival, duration of visit, number of flowers probed, number of perches, duration of longest perches, any vocalizations and territorial behaviors. Two species of hummingbird fed at B. solanoides throughout this study: booted racket-tails (Ocreatus underwoodii) and violet-tailed sylphs (Aglaiocercus coelestis). The linear regression run between visitation frequency and number of flowers showed a significant, positive correlation, and the regression of visitation frequency and nectar sugar concentration was insignificant, showing that these species value quantity of flowers over quality of nectar at this particular resource. Very few male violet-tailed sylphs visited B. solanoides, but instead were seen feeding on inflorescences of other plants, possibly because B. solanoides was declining as a resource at time of the season. Unexpectedly, females of both species were predominantly the territorial individuals, and three individuals were distinguishable based on physical traits and perching locations. These three females visited their bush more times than all other visits combined, and exhibited territorial behaviors, lengthy perches, and vocalizations.

Disciplines

Animal Studies | Community-Based Research | Latin American Studies | Life Sciences | Other Animal Sciences | Zoology

 

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