Updated on September 17, 2021. All states affected by the mysterious bird illness of summer 2021 have lifted their do-not-feed recommendations (see below for links). No cause has yet been determined, but cases are no longer being reported. Links to state-by-state information are compiled at the end of this article.
A joint statement of the Cornell Lab of Ornithology and the Cornell University College of Veterinary Medicine.
In May through July, 2021, a newly emerging illness causing crusty eyes, tremors, and paralysis among songbirds caused widespread concern. The illness affected mainly fledgling birds in eastern states including Virginia, Maryland, Delaware, New Jersey, Pennsylvania, West Virginia, Kentucky, Ohio, Indiana, and District of Columbia. Many of these states issued advisories to cease providing food or water to birds out of an abundance of caution. These recommendations have been lifted (see below for links to state by state information).
In July 2021, we prepared the following statement with the help of the Cornell University College of Veterinary Medicine to summarize the state of knowledge of experts in state and federal agencies who are working to understand this event. For a detailed summary of the situation, please see this statement from the U.S. Geological Survey. The Cornell Lab of Ornithology does not have experts studying the situation, and the illness was never reported in New York state.
The main points to know
- Please follow your own state’s guidelines on whether to take down bird feeders. Find your state agency here.
- Although little is known about the cause, confirmed cases of the illness are no longer being reported .
- No human health or domestic livestock/poultry issues have been reported.
- The illness is not caused by any of the major known bird diseases such as West Nile, salmonella, avian influenza, House Finch eye disease, Trichomonas parasites, etc.
- The species most frequently affected are fledgling (juvenile) Blue Jays, Common Grackles, European Starlings, and American Robins, along with a few other species. Symptoms include crusty eyes and neurological signs such as tremors or partial paralysis.
- We don’t know if the illness is caused by a disease organism (i.e., virus, bacteria, or parasite), or if it’s the result of a toxic substance in the landscape.
- If it’s a disease, we don’t know how it’s transmitted. It might be directly transmissible from bird to bird (like a cold or the flu), or might require a vector (such as with malaria, where a mosquito transmits the illness).
What to do if you find a sick or dead bird
- Avoid handling birds unless necessary. If you must handle them wear disposable gloves, or use an inverted plastic bag over your hand to pick up a dead bird.
- Keep pets (including pet birds) away from sick or dead wild birds as a standard precaution.
- Report the sick or dead bird to your state wildlife conservation agency for further instructions and to help them track this event.
What to do about bird feeders
- Please follow your own state’s recommendations on whether to take down bird feeders. See below for links to state advisories.
- In states without specific guidance on feeders, the Cornell Lab does not currently recommend taking them down, given the lack of confirmed cases and uncertainty about how the disease is transmitted. However, it is fine to take down feeders as an extra precaution if you prefer, since there is plenty of natural food for birds at this time of year.
- It’s always a good idea to keep feeders clean by washing with a dilute bleach solution. Here’s more about how to clean feeders.
Specific information for New York state residents
- There have been no confirmed cases of the illness yet in New York state.
- Because of the lack of confirmed cases in New York state, and uncertainty about how the disease is transmitted, the Cornell Lab is not recommending that feeders in New York be taken down at this time. Note that Audubon New York has recommended taking down feeders, and there is no harm in doing that out of an abundance of caution.
- It’s always a good idea to regularly clean your feeders.
Updated September 13, 2021:
- Delaware — Update: Delaware lifted its do-not-feed recommendation on August 24
- Indiana — as of a Sept. 10 update, Indiana’s do-not-feed recommendation has been lifted
- Kentucky — in an Aug. 19 update, Kentucky lifted its do-not-feed recommendation
- Maryland — in an Aug. 17 update, Maryland lifted its do-not-feed recommendation
- New Jersey — in an Aug. 31 update, New Jersey lifted its do-not-feed recommendation
- Ohio — in a Sept. 8 update, Ohio lifted its do-not-feed recommendation
- Pennsylvania — Update: Pennsylvania lifted its do-not-feed recommendation on August 13
- Virginia — Update: Virginia lifted its do-not-feed recommendation on August 19
- Connecticut (no confirmed cases; do-not-feed recommendation lifted on August 20)
- Massachusetts (no confirmed cases; do-not-feed recommendation amended on August 30)
- Rhode Island (no confirmed cases; do-not-feed recommendation lifted on August 26)
- Find your state wildlife agency here
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