A mysterious illness has been sickening songbirds in the eastern United States since May of this year, and researchers are working to discover the cause.
The illness was first discovered in Washington, DC, and hundreds of cases in nine Midwestern and Eastern states have been reported since.
Science Magazine reported that researchers have found that certain species of bird, such as blue jays and American robins, seem to be more susceptible to being infected. Young birds also may be more susceptible.
The birds experience lethargy and become blinded by crusty patches that grow over their eyes, the magazine reported.
Researchers have ruled out some causes, such as Salmonella bacteria and certain parasites, but the answer as to what is sickening and killing the birds is still not known.
Some officials have also told Science Magazine that there are some signs that the outbreak could be lessening, as fewer birds have been brought to some of the rehab centers.
Science Magazine said officials continue to ask people to take steps to slow the spread of the illness, such as burying dead birds and removing bird feeders where the animals might congregate.
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