Source: http://www.wildlifeextra.com/go/news/be ... ities.htmlDefects leave birds struggling to feed themselves
The highest rate of beak abnormalities ever recorded in wild bird populations is being seen in a number of species in the Northwest and Alaska, but it has not yet been possible to isolate a cause for the defects.
Black-capped chickadees, Northwestern crows and other birds are being impacted by the problem, which affects their ability to feed and clean themselves and could signal a growing environmental health problem.
In birds affected by what scientists term ‘avian keratin disorder', the keratin layer of the beak becomes overgrown, resulting in noticeably elongated and often crossed beaks, sometimes accompanied by abnormal skin, legs, feet, claws and feathers.
‘The prevalence of these strange deformities is more than ten times what is normally expected in a wild bird population,' said research biologist Colleen Handel with the USGeological Survey, which has just published its findings. ‘We have seen effects not only on the birds' survival rates, but also on their ability to reproduce and raise young. We are particularly concerned because we have not yet been able to determine the cause, despite testing for the most likely culprits.'
Now affecting 17 per cent of adult northwestern crows in coastal Alaska
The disorder, which has increased dramatically over the past decade, affects 6.5 per cent of adult black-capped chickadees in Alaska annually. Beak deformities in this species were first observed in the late 1990s and biologists have since documented more than 2,100 affected individuals. Increasing numbers of other species have also been observed with beak deformities throughout Alaska, British Columbia, and Washington. An estimated 17 per cent of adult northwestern crows are affected by avian keratin disorder in coastal Alaska.
Could something be fundamentally wrong with Alaska's ecosystem?
Beak deformities in birds can be caused by many different factors, including environmental contaminants, nutritional deficiencies, and bacterial, viral, fungal or parasitic infections. In the past, other large clusters of beak deformities have been associated with environmental pollutants such as organochlorines in the Great Lakes region and selenium from agricultural runoff in California. These biological discoveries were the first indication that something was wrong in the ecosystem and led to efforts that ultimately corrected the problem.
‘We're seeing ecologically unique species affected across a wide range of habitats. The scope of this problem raises concern about environmental factors in the region,' said USGS wildlife biologist Caroline Van Hemert.
The increasing occurrence of deformities in multiple bird species with broad geographic distribution suggests that avian keratin disorder is spreading and may be an indication of underlying environmental health problems. Additional studies by the USGS will continue to investigate why so many birds are currently affected in Alaska and the Pacific Northwest. Current research is focused on understanding the disease and potential causes of the disorder.
The picture on the link is quite odd. It would be interesting seeing a bird look like that. It must also be hard for them to eat, clean themselves, ect. with a deformed beak. It is sad that the rate is higher than expected in Alaska, so hopefully scientists can find out what's causing this disorder.