Black-capped Chickadee, USGS photo

Over the past several years, Alaskans have witnessed a startling increase of beak deformities among local birds.  Large numbers of Black-capped Chickadees and smaller numbers of many other species of birds have appeared with grossly overgrown and crossed beaks.

We began research in 1999, and have since identified nearly 2,000 deformed Black-capped Chickadees in south-central Alaska—the highest concentration of such abnormalities ever recorded in a wild bird population anywhere!  More recently, rapidly increasing numbers of other species, including Downy Woodpeckers, Northwestern Crows, Steller’s Jays, and Black-billed Magpies have also been reported with beak deformities by biologists and local residents throughout the state.

Although we do not yet know the source of this widespread problem, we continue to investigate potential causes, including environmental contaminants, nutritional deficiencies, and disease.  Nearly all of the species affected are year-round residents, and we suspect that factors responsible for this cluster of deformities may be unique to Alaska and the Pacific Northwest.  We are currently pursuing additional studies to determine where these deformities are occurring and why.  Reports from the public help us to determine where and how many birds are affected.  If you see a bird with a deformed beak, please contact us.

All information on this website has been summarized from our recently completed report and should be cited as:

Handel, C. M., L. M. Pajot, S. M. Matsuoka, K. A. Trust, J. M. Stotts, J. Terenzi, and S. L. Talbot. 2006. Potential Role of Environmental Contaminants in the Pathology of Beak Deformities among Black-capped Chickadees in South-central Alaska. Unpublished final report. Project ID: 1130-7F22. U. S. Geological Survey, Alaska Science Center, Anchorage, Alaska. [PDF file 15 MB]