Bird of the Week: Cerulean Warbler


Although brightly colored, the sky-blue Cerulean Warbler is not easy to spot: It nests high in the forest canopy, where it can often be detected only by its rapid, buzzy song.


Unfortunately, the Cerulean Warbler has become even harder to find. Its population has declined by about 70 percent in the past 40 years, making it one of North America’s most threatened migrant songbirds. The greatest threats are habitat destruction and fragmentation on both breeding and wintering grounds due to logging, mountaintop mining, and agricultural development.



Other threats to Cerulean Warblers include nest parasites such as Brown-headed Cowbirds. These and other predators easily invade fragmented forests and can lower the warbler’s breeding success.


Reversing the species’ rapid decline is one of ABC’s top priorities. In North America, ABC works with the Central Hardwoods and Appalachian Mountain Joint Ventures (AMJV) to protect important breeding habitat for Cerulean Warblers. The latter recently received an $8 million grant through the U.S. Department of Agriculture’s Regional Conservation Partnership Program to restore even more habitat, working with more than a dozen partners. The AMJV-led project will enhance 12,500 acres of forest habitat on private lands for Cerulean Warblers and other wildlife. Approximately 1,000 acres of reclaimed mine lands will also be restored.


ABC and partners also used studies on forest management techniques for the warblers to create a Best Management Practices document for land managers and landowners. With these techniques, we are figuring out how to get more Cerulean Warblers to use an acre of forest by thinning certain trees, allowing other trees to grow larger and providing the more complex canopy structures needed by these birds.


On the species’ South American wintering grounds, ABC and Colombian partner Fundación ProAves initiated the Cerulean Warbler Conservation Corridor in 2008, working to enhance habitat quality by planting trees on private lands between the Pauxi Pauxi and Cerulean Warbler Reserves managed by ProAves. This work benefits other migratory birds such as Canada and Golden-winged Warblers, and threatened birds found nowhere else, including Gorgeted Wood-Quail and White-mantled Barbet. The partners have also produced a Cerulean Warbler Conservation Plan in English and Spanish.


Recent expansion of Ecuador's Narupa Reserve has preserved even more valuable wintering habitat for the Cerulean Warbler and many other migrants like Olive-sided Flycatcher. ABC is currently supporting monitoring work for Cerulean and other warblers in northern Peru and Ecuador as well.


Cerulean Warbler conservation will be a focus of the 2015 Biggest Week in American Birding, supported by ABC and led by our partners at Black Swamp Bird Observatory.  The bird also plays a role in the best-selling novel Freedom by ABC’s board member Jonathan Franzen.


See a clip of Cerulean Warbler in ABC’s video, “20 Years of Results for Birds".