Colleen Handel, Ph.D.
Population ecology of passerines and shorebirds, behavioral ecology, population monitoring, and sampling design.
Science and Products
Filter Total Items: 20
Literature Cited for Beak Deformities
Literature Cited in the Beak Deformity web pages
Prevalence, Distribution and Timing of Beak Deformities in Birds
The rates of beak deformities documented in Black-capped Chickadees and American Crows in Alaska are the highest ever recorded within a wild bird population anywhere.
Physical Description of Beak Deformities
The most commonly observed physical abnormalities among Alaskan birds are overgrown or crossed beaks.
Effects of Beak Deformities on Birds
Birds with beak deformities often have difficulty foraging and preening and may not be able to keep themselves warm and well-fed during cold winter months. Although some birds with beak deformities breed successfully, they typically encounter more challenges than normal birds.
Background of Beak Deformity Research
Large numbers of Black-capped Chickadees with abnormal beaks were reported in south-central Alaska in the late 1990s. More recently, similar beak deformities have appeared in other species throughout the state. At least 30 Alaskan bird species are affected and the geographic extent of the problem appears to be growing. In addition to Alaskan observations, we have received increasing numbers of...
Species Affected by Beak Deformities
At least 30 Alaskan bird species are affected by beak deformities and the geographic extent of the problem appears to be growing. In addition to Alaskan observations, we have received increasing numbers of reports from other parts of North America and Europe.
Science and Products
Filter Total Items: 20
Literature Cited for Beak Deformities
Literature Cited in the Beak Deformity web pages
Prevalence, Distribution and Timing of Beak Deformities in Birds
The rates of beak deformities documented in Black-capped Chickadees and American Crows in Alaska are the highest ever recorded within a wild bird population anywhere.
Physical Description of Beak Deformities
The most commonly observed physical abnormalities among Alaskan birds are overgrown or crossed beaks.
Effects of Beak Deformities on Birds
Birds with beak deformities often have difficulty foraging and preening and may not be able to keep themselves warm and well-fed during cold winter months. Although some birds with beak deformities breed successfully, they typically encounter more challenges than normal birds.
Background of Beak Deformity Research
Large numbers of Black-capped Chickadees with abnormal beaks were reported in south-central Alaska in the late 1990s. More recently, similar beak deformities have appeared in other species throughout the state. At least 30 Alaskan bird species are affected and the geographic extent of the problem appears to be growing. In addition to Alaskan observations, we have received increasing numbers of...
Species Affected by Beak Deformities
At least 30 Alaskan bird species are affected by beak deformities and the geographic extent of the problem appears to be growing. In addition to Alaskan observations, we have received increasing numbers of reports from other parts of North America and Europe.
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government