A mysterious avian illness appears to have spread from the eastern coast of the United States to the Midwest and southern US. While there have been no cases identified in Wisconsin, the illness has continued to spread west as far as Ohio and Indiana.
While the origin and other aspects of the illness are still being investigated by multiple wildlife laboratories, the symptoms consistent with the illness include: eye swelling, crusty discharge and neurological signs. The illness has generally been found in fledgling and juvenile blue jays, common grackles, European starlings and American robins, and has been fatal in many cases.
No causes of the illness or mortality have been identified at this time. Natural resource management agencies in the states with reported cases and the National Park Service are working with multiple laboratories to investigate the cause of the illness.
Some have noted that the symptoms of this illness are similar to House Finch eye disease, a bacterial illness that also originated on the east coast in the 1990s. Afflicted finches exhibited swollen, runny eyelids that could lead to total blindness. However, House Finch eye disease does not cause the neurological symptoms present with the new illness.
Wildlife agencies have been testing for months to identify the illness and have been able to rule out several common bird pathogens, as well as West Nile virus and avian flu. The disease currently does not pose a risk to transmit to humans.
The first reports of this illness began in May when wildlife professionals received reports of sick birds in Washington D.C., Maryland, Virginia, West Virginia and Kentucky. To date, the Southeastern Cooperative Wildlife Disease Study (SCWDS) and other wildlife agencies have received thousands of reports of sick and dead birds.
Beginning in late June, the Wisconsin Department of Natural Resources (DNR) received scattered reports of birds with swollen, crusty eyes. The DNR is continuing to investigate reports of birds with these symptoms, but has stated that there could be other causes for these symptoms unrelated to the illness in the eastern states.
Kaitlin Svabek of the Madison Audubon Society suggested in a WPR interview that bird feeders should be taken down, stating “We are recommending out of an abundance of caution the preventative measures recommended by the National Wildlife Health Center and that would be to take down feeders and bird baths.”
This may be a disappointment to many bird watchers, but illnesses can easily be spread between the birds congregating at these sites. The removal of bird feeders also has little effect on the overall health of bird populations since there is abundant vegetation during the summer.
With overall bird populations already declining due predominantly to habitat loss, it is vital that we take precautions to prevent an outbreak of an unknown disease. By simply taking down bird feeders and baths, we can significantly reduce the risk of transmission. If any citizen spots a sick or dead bird with these symptoms, they should report the sighting to a local DNR office.