Reproductive ecology of White-throated Sparrows

About the Project

The White-throated Sparrow (Zonotrichia albicollis) has been the subject of intermittent study based at the AWRS. Early research by Dr. Bruce Falls about avian song, reproductive behaviour, and parental care developed techniques, such as song playback, that revolutionized ornithology and are widely used for the study of birds today. For this research, alongside his lifelong dedication to nature protection, was recognized with the Order of Canada (2016).

Since 2005, Dr. Scott Ramsay has been conducting research in Algonquin Park focusing on the causes and consequences of variation among female White-throated Sparrows in the timing of nest initiation, and the number and size of eggs laid. Factors that may influence these variables are spring temperature and precipitation, and patch-level habitat differences such as the amount of food available leading up to egg-laying and the food availability for nestlings when they hit their peak demand. Females may also base some of their decisions on the characteristics of their partners, including the prospects male provisioning effort, which in White-throated Sparrows is related to morph (tan-striped vs. white-striped individuals).

Interesting patterns are emerging from the data, including a strong influence of clutch initiation date on the likelihood of a nest surviving to fledging. Dr. Ramsey is also interested in various aspects of the songs of male White-throated Sparrows including their utility as an indicator of male identity in the absence of banding information for estimating year-over-year survival rates. Finally, I am also using stable isotope analysis of feathers grown prior to spring migration to estimate where the White-throats that breed in Algonquin Park spend the winter. The data so far suggest that males winter farther north than females, tan-striped individuals winter farther north than white-striped individuals, and many of the birds in our population never leave Ontario in the winter.