Electronic Thesis and Dissertation Repository


Master of Science




Morbey, Yolanda E.

2nd Supervisor

Guglielmo, Christopher G.



Differential migration timing between distinct classes of individuals is commonly observed in songbirds, however, the underlying behavioural mechanisms of differential timing are still uncertain for most species. My research applied a suite of advanced techniques to examine differential migration timing (by sex and morph) and its underlying behavioural mechanisms (refuelling rate, stopover duration, and wintering latitude) in spring migrating White-throated Sparrows (Zonotrichia albicollis) at a key stopover site. Protandry was the only form of differential migration timing observed, with males arriving at stopover on average 11 days earlier than females. Males and females had similar refuelling rate, stopover duration, and wintering latitude, suggesting that other behavioural mechanisms must contribute to the high level of protandry observed. Migration timing, stopover behaviour, and wintering latitude did not differ between morph classes. This study adds to the mounting evidence that differential migration timing does not result from differences in stopover behaviour.