American Kestrel

All species of North American raptors, including the American Kestrel (Falco sparverius), are monitored during migration by counting individual birds at watch-sites that are stationed along major migratory flyways. Scientists then use this migration-count data to estimate and monitor changes in population trends. However, American Kestrels are shifting the timing and patterns of their migratory movements, which could make inferring population trends from migration-counts difficult. If we want to maintain the utility of migration-counts into the future, we need to develop methods for understanding which populations of American Kestrels are being monitored at migration watch-sites, and how migratory movements of those populations are changing over time. Once we can track specific breeding populations across the annual cycle, then we can determine which populations are declining and where they are most limited.

With the help of numerous partners (see below), the Bird Genoscape Project developed high-resolution molecular markers to identify breeding populations of American Kestrels in North America. We scanned the genomes of 197 individuals from 12 sampling locations across the breeding range to identify population structure. In total, we’ve identified the existence of 5 genetically distinct populations of the American Kestrel – East (blue), West (yellow), Texas (orange), Florida (purple), and Alaska (aqua). These 5 populations can serve as the foundation for American Kestrel conservation and management.

Our work is ongoing with the American Kestrel, as we continue to collect additional samples across the wintering grounds to hopefully be able to discern where the Alaska (aqua) and Texas (orange) breeding populations over winter.