Canada Warbler Demography

Summer Survival and Winter Wanderings

Stephanie’s research focuses on the Canada Warbler (Cardellina canadensis), a small neotropical migrant songbird which has declined in apparent abundance over the past several decades. While most of its breeding range is within Canada as the name suggests, this charismatic species is also distributed south at high elevations of the Appalachian corridor through West Virginia. Apparent population increases in the state raise the question: what are the annual survival and reproduction rates of Canada Warbler breeding in the region, and what role do the environmental conditions play in shaping population demography?  Additionally, where does this population winter, and are the environmental conditions outside of the breeding grounds contributing to the population trends we observe in West Virginia?

Over the course of three years, we captured over two hundred Canada Warblers and marked them with unique combinations of plastic color bands to estimate the likelihood of an individual surviving from one year to the next. In the third summer of the project, nests were located and observed using motion-triggered game cameras to determine probability of the nestlings surviving to fledging. To establish groundwork for full annual cycle modeling, geolocators were attached to a sample of adult male birds and retrieved the next year to determine the overwintering location and migratory flyways used by this central Appalachian population.