Department receiving fewer reports of sick and dying birds while researchers continue efforts to determine cause.

Published 11:34 am Wednesday, August 4, 2021

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FRANKFORT, Ky.- On Wednesday, the Department of Fish and Wildlife Resources provided an update about the ongoing investigation of an unexplained illness affecting birds in Kentucky and elsewhere.

Kentucky Fish and Wildlife has received more than 2,000 reports of sick or dying birds to its online reporting system since the portal went live on June 17. The number of daily reports coming in has steadily declined since the end of June.

Staff continue to review all reports and believe approximately 265 of the reports are related to the unexplained illness. Several reported bird deaths were due to normal causes of mortality. Other reports have contained limited information and were inconclusive.

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Based on its analysis, Kentucky Fish and Wildlife continues to encourage residents in six counties (Boone, Bullitt, Campbell, Jefferson, Kenton and Madison) to stop feeding birds and follow other statewide guidance.

“The counties where we have received the most reports suspected to be linked to the unexplained illness were Jefferson, Kenton and Boone, in that order,” said Kate Slankard, avian biologist with Kentucky Fish and Wildlife. “It is important to note that it is difficult to distinguish which county is actually more affected because of reporting bias associated with densely populated areas.”

At this time, a definitive cause for this bird illness has yet to be identified.

Wildlife and natural resource agencies in the District of Columbia, Maryland, Virginia, West Virginia, Delaware, New Jersey, Pennsylvania, Ohio, Indiana and Kentucky, along with federal agencies, are continuing to work with diagnostic laboratories to investigate the cause of the unexplained illness. Transmission electron microscopy and additional diagnostic tests, including microbiology, virology, parasitology, and toxicology are ongoing.

The following pathogens have not been detected in any birds tested, based on results received to date: Salmonella and Chlamydia (bacterial pathogens); avian influenza virus, West Nile virus and other flaviviruses, Newcastle disease virus and other paramyxoviruses, herpesviruses and poxviruses; and Trichomonas parasites.

“There are likely multiple factors contributing to this mortality event,” said Dr. Christine Casey, wildlife veterinarian with Kentucky Fish and Wildlife. “The new problem appears to be complex and labs are working on understanding the possible role of bacteria and toxicology in the affected birds.

“Determining primary and secondary causes for the problem may be necessary and this complicates and lengthens the diagnostic process.”

A common disease of finches, House Finch eye disease, which has similar symptoms and is observed annually in Kentucky, does not appear to be associated with this new unexplained illness that primarily is affecting juvenile common grackles, blue jays, European starlings and American robins. Unfortunately, House Finch eye disease is common in warmer months and also appears to be circulating in Kentucky at this time.

People who observe sick house finches or goldfinches at their feeders should take down their feeders and follow the cleaning protocol outlined below.

Kentucky Fish and Wildlife continues to recommend the public follow these guidelines:

In Boone, Bullitt, Campbell, Jefferson, Kenton and Madison counties:

• Cease feeding birds until further notice (when this issue has been resolved);


• Clean feeders and birdbaths weekly with a 10-percent bleach solution (one-part bleach mixed with nine parts water), rinse with water and allow to air dry;

Avoid handling birds unless necessary. If you do handle them, wear disposable gloves. If picking up a dead bird, place an inverted plastic bag over your hand to avoid direct contact with the bird; and

Keep pets (including pet birds) away from sick or dead wild birds as a standard precaution.

If sick or dying birds are observed at any feeders or birdbaths, the department recommends taking them down for two weeks and cleaning them in a 10-percent bleach solution.

“Feeders and baths congregate animals and tend to increase the transmission of pathogens and create a source of contamination for visiting birds,” Casey said. “While this unknown bird illness investigation is ongoing, it is likely caused by several factors and taking down bird feeders in affected counties is a wise precaution. We are asking for your assistance with protecting Kentucky’s songbirds.”

If you encounter sick or dead birds, please utilize the online reporting system provided by the department. Access the reporting system online at or through the Unexplained Bird Illness webpage on the department’s website at

If you must remove dead birds, place them in a sealable plastic bag and dispose of the bag in a secured outdoor trash receptacle or bury them deeply in the ground.

Kentucky Fish and Wildlife will post additional information on its website and social media channels as diagnostic results become available.