Collaborative Research: Sexual Selection on Male Ornaments PI: Peter Dunn, Corey Freeman-Gallant
Males often possess ornamental traits such as long tails and bright colors that they use to attract mates. These ornaments may be favored by female choice or male-male competition. Female choice is likely to act on different ornaments than male-male competition, particularly when some ornaments are more revealing of male quality than others. For example, in species with both carotenoid (red, yellow) and melanin (black, brown)-based ornaments, it appears that females often focus their mate choice on the carotenoid-based ornaments, which are generally considered to be better indicators of male condition than ornaments with melanin pigments. Surprisingly, we have discovered two populations of a monogamous bird, the common yellowthroat, in which male reproductive success is related to the size of a carotenoid-based ornament (yellow bib) in one population (New York) and a melanin-based ornament (black facial mask) in another population (Wisconsin). Our study will examine sexual selection on each plumage ornament in both populations.
This study will 1) use aviary experiments to identify which ornaments are favored by female choice and male-male competition, and 2) determine if the differences between populations are caused by different mechanisms of selection operating on different ornaments. Common yellowthroats are one of only a handful of species in which researchers have been able to identify the sires of most young, including extra-pair young, and, as a consequence, make an estimate of the full force of selection on male ornaments.
One of the broader impacts of this project will be to foster training of students in collaborative research, which will give them a better perspective on how science is conducted. To facilitate this training, the PIs will exchange students between their two institutions (one a small undergraduate institution, the other a large graduate program) each year for both the field and laboratory components of the project.
