About This Project

Males of many hummingbird species perform vigorous courtship displays which seem to push the limits of their flight abilities. My project will test whether an aerial courtship display is a signal of flight performance, and if these acrobatic displays predict male reproductive success (fitness). By extracting DNA from feathers, a relatively under-utilized technique, I can assign paternity to nestlings and test my hypotheses without harming the birds.

Ask the Scientists

What is the context of this research?

Vigorous behavioral displays may serve to highlight important differences among males (Darwin, 1871) that may provide information about “quality” to females (Andersson, 1994). Choosy females should benefit in that their offspring may inherit genes from their fathers that confer high quality (Fisher 1915; Williams, 1966). Displays may advertise quality through demonstrations of athletic behaviors (e.g., locomotion ([Byers et al., 2010]). Black-chinned Hummingbirds (Archilochus alexandri) provide a superb system for studying courtship and locomotor behaviors because males perform courtship-flight displays that are associated with accentuated wing sounds (Feo and Clark, 2010). Wing sounds may serve as a signal of flight performance, and have evolved in several bird species (Bostwick, 2006).

What is the significance of this project?

Where most studies have focused on morphological indicators of male quality, my research will analyze variation in male courtship-flight behavior to better understand how locomotor abilities may be honestly conveyed to females, and how these athletic performances affect male fitness. To date, few studies have linked male locomotor performance with reproductive success (Husak et al., 2006; Barske et al., 2010), and so this project will advance our knowledge of animal courtship, communication, and locomotion.

What are the goals of the project?

The goals of this project are to test the hypotheses that courtship-flight performance honestly advertises male flight abilities, and that the display is related to male reproductive success. DNA markers for paternity analyses have been developed for other hummingbirds, but not A. alexandri. A secondary goal of this study is to confirm the utility of previously published DNA markers in order to use feathers to sample DNA from nestlings, mothers, and potential fathers.

This study also will incidentally address a long-standing question in hummingbird natural history. In many other hummingbird species, a small number of males obtain most of the matings. But we do not know whether this reproductive skew occurs in A. alexandri.