Song learning and syntax patterns in the American robin and the soil characteristics of bank swallow nest sites
My dissertation is based on research in two very different subjects. The first two chapters report on my work with song learning and song element sequence patterns, or syntax, in the American Robin, while the last chapter is based on my work with soil samples from Bank Swallow colonies and other eroding slopes along the Connecticut River. American Robins are one of the most common and well known birds in North America, but very little is known about how robins acquire a song repertoire, or how robins transition through the different sounds in their repertoire when singing. Male robins typically have between 15 and 25 whistle song elements in their repertoire. When singing, male robins string these elements together, often singing 3 to 6 elements in a row. My analyses of recordings of young robins raised in acoustic isolation and of wild robins recorded at three locations in Western Massachusetts suggest that robins learn song elements through both imitation and improvisation/invention. I also found that robins sing the song elements in their repertoire in a complex non-random pattern, and that these patterns varied among the recording locations and among individuals. Bank Swallows nest by burrowing into the exposed soil of eroding banks, typically along rivers and streams. My research suggests that Bank Swallows tend to avoid nesting in banks that are composed primarily of sand, preferring slopes with a mixture of sand and silt, with larger colonies forming in areas with higher proportions of silt to sand.