USGS Science in Alaska
Epidemic of Beak Deformities (Avian Keratin Disorder) among Wild Bird Populations
A study to determine the cause of avian beak deformities throughout south-central Alaska
Handel, Colleen M.
Van Hemert, Caroline R.
Start Year: 2005
End Year: 2017
USGS Mission Area and Program:
Ecosystems → Wildlife Program
Environmental Health → Contaminant Biology
USGS - Avian Health and Disease Program
Beak Deformities web site
Since January 1998, about 2000 birds of 30 different species have been reported in Alaska with grossly deformed beaks. Most sightings have been concentrated in south-central Alaska but recently a smaller cluster of observations has been reported from the Pacific Northwest (notably Puget Sound area). Outside of Alaska, we have received about 300 reports of individuals of over 80 species of wild birds with similarly deformed beaks scattered across North America. In Alaska, prevalence of these abnormalities appears to be highest among black-capped chickadees and various corvid species, including northwestern crows, Stellarís jays and black-billed magpies. The geographic distribution of deformities and high prevalence among resident birds suggest an acute, ecosystem-wide problem, but the cause and geographic origin of deformities are still unknown. In this research project we are tracking the spatial and temporal distribution of the deformities across North America, documenting the species affected, determining effects of the deformities on reproduction and survival, and testing for contaminants, disease, parasites, nutritional imbalances, and other factors as potential causes.
Project metadata record