Kentucky Warbler Migration from the Great Plains to the Tropics

While it has long been known that many songbirds complete vast migrations from the temperate zones to the tropics each year, surprisingly few species have been tracked along their entire journey across the hemisphere to specific nonbreeding areas. Given that events on the wintering grounds and along migration can have a large impact on birds that breed in North America, the need for understanding the full annual cycle of migratory species has never been greater.

Enter the Kentucky Warbler, a striking yellow and black ground-dwelling forest bird of southeastern North America. In Nebraska, this species reaches its northwestern range limit, breeding only in the largest tracts of oak-woodlands at the extreme southeast corner of the state. Little is known about this species at the edge of its range, and no individual of this species has ever been tracked along its migration or to its wintering grounds. Populations of Kentucky Warblers have been in relative decline since the end of last century, and it remains unclear if conditions during the breeding season or the nonbreeding season are challenging the recovery of this incredible warbler. Studying the migratory routes and non-breeding grounds of birds in our region not only establishes a connection between the Great Plains and tropical ecosystems, but this also helps identify potential conservation opportunities beyond our borders.

In 2025, biologists from Audubon Great Plains and the Nebraska Game and Parks Commission initiated a project tracking Kentucky Warblers to discover their migration routes and establish where birds breeding at range periphery spend the nonbreeding season. Researchers deployed light-level geolocators to track these small birds over the course of a year. This technology has been used across many species of warblers since the mid-2010s, and was recently used to discover the unique migrations, wintering grounds and high survival of Ovenbirds breeding in the northwestern regions of Nebraska.

In 2026, two Kentucky Warblers tagged in the previous year were recaptured on their breeding grounds and data from one geolocator was recovered. Early analysis on this tag points to a South American wintering site, which would mean Kentucky Warblers in the Great Plains complete two 3,000+ mile journeys each year between breeding and wintering locations. Hopefully a few more geolocators can be recovered and additional data processing can reveal even more about these amazing birds as this project continues into 2027.