Alaska Science Center

Epidemic of Beak Deformities (Avian Keratin Disorder) among Wild Bird Populations

A study to determine the cause and distribution of avian beak deformities throughout south-central Alaska.


Since January 1998, thousands of birds of 30 different land bird species have been reported in Alaska with grossly deformed beaks. Most sightings have been concentrated in south-central Alaska, primarily in black-capped chickadees. Outside of Alaska, there have been about 300 reports of individuals of over 80 species of wild birds with similarly deformed beaks scattered across North America. 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. Research objectives are to determine the causative factors of the disease, geographic distribution, and determine possible management actions to limit continuation of the deformities in birds. Methods thus far to understand the disease have involved contaminant screening, genetic defect evaluation, changes in forage quality, bone and keratin evaluation, and viral and bacterial factors.
Title Type
Blood Parasite Infection Data from Northwestern Crows (Corvus caurinus), Alaska, 2007-2008Data
Blood serum chemistry of wild Alaskan Black-capped Chickadees (Poecile atricapillus) with Avian Keratin Disorder Publication
Novel picornavirus associated with avian keratin disorder in Alaskan birdsPublication
Avian keratin disorder of Alaska black-capped chickadees is associated with Poecivirus infectionPublication
Genetic Data Associated with Avian Keratin Disorder and Poecivirus in Black-capped Chickadees, Alaska, 2001-2017Data
Beak Deformities web siteProject Website


Handel, Colleen M., 907.786.7181
Van Hemert, Caroline R., 907-786-7167

Status: completed
Start Year: 2005
End Year: 2019

Project Sites

Matanuska Valley

USGS Mission Area and Program
EcosystemsWildlife Program
Environmental Health → Contaminant Biology

Major Initiatives
USGS - Wildlife Disease Program