Date of Award


Publication Type

Master Thesis

Degree Name



Biological Sciences


Animal Behaviour, animal culture, Birdsong, songbird, sparrow, vocal learning


Daniel Mennill




In this thesis I study the effect of acoustic similarity on song selection and territorial aggression in Savannah Sparrows (Passerculus sandwichensis). In my first data chapter I studied the phenomenon of overproduction and selective attrition in Savannah Sparrow song development. Four years of field data reveal that Savannah Sparrows routinely exhibit overproduction of their song repertoires; more than half of young males express more than one song type early on in their first breeding season, before undergoing attrition to a single song. I found that the attrition of song types is a selective process, with males retaining songs that were more similar to their territorial neighbours. In my second data chapter I examined whether birds whose songs were similar to their neighbours benefited from lower levels of territorial aggression. Males that sang songs that were dissimilar to their neighbours faced higher levels of territorial aggression as indicated by higher numbers of aggressive calls detected in their territories. I conclude that birds which learn songs dissimilar to their neighbours face elevated levels of territorial aggression at the onset of the breeding season. My results provide support for the theory that vocal learning in songbirds can allow males to produce a song type that matches local cultural traditions, providing a benefit in terms