Office of Undergraduate Research

The Function of Bird Colors

We are studying why many species of birds are brightly colored. We study this question from both a function (physiological) and evolutionary perspective. This particular project will examine why male common yellowthroats, a small warbler, vary in the size of their two main ornaments: a black facial mask and yellow bib (throat and breast). We will catch birds at the UWM Field Station in Saukville, measure them and take blood samples to examine plasma carotenoids (used to pigment the yellow feathers) and other measures of physiological condition and health. We may also examine museum specimens to see how much these ornaments vary throughout the range of the species. Our results indicate that these two ornaments are used by females to choose mates, but interestingly, one ornament (mask size) is preferred in Wisconsin, and the other (yellow bib) is preferred in New York. Thus, our objective is to better understand this geographic variation and why it occurs.

Tasks and responsibilities:

Depending on their interests, students will be involved in field work (capture, handling of birds), processing and analysis of blood samples for carotenoid content (using a spectrometer) and immunoglobins (a more advanced procedure that will take more training). Students will also use image analysis software to measure the size of male ornaments (from photos). There will also be an opportunity to learn data entry and statistical analysis, and, possibly, co-authorship on a scientific paper.