Sarah Goodwin is a Ph.D. student in the OEB program, and will study singing behavior of small songbirds. In particular, she is interested in plasticity of song, and how song flexibility varies among individuals. To explore these questions, Sarah will study the "fee-bee" song of Black-capped Chickadees. Black-capped Chickadees are small resident songbirds common at bird feeders in Massachusetts. In the winter, Chickadees form small flocks with pecking orders such that one individual is the most dominant, followed by the second most dominant, on down to the most subordinate individual. In early spring and summer, flocks disperse and males defend territories and attract mates using song. One song is a two-note "fee-bee" or "hey sweetie." Although the song is similar across most of their range, Black-capped Chickadees occasionally change the frequency of the notes, producing the song a higher pitch or a lower pitch. Sarah hopes to test if singing males can respond to changes in their acoustic environment by intentionally altering the frequency of their songs. Furthermore, Sarah is curious if this flexibility varies from individual to individual, and if more dominant males are more or less flexible than subordinate males.