Help Us Track Sick Birds With Project FeederWatch

November 26, 2013
male and female House Finch A healthy male (right) and female House Finch.

House Finches may be found at feeders across much of North America, and if you see these little birds, we’d like to know about it. Specifically, our scientists want to know if the birds you see appear healthy or if they have redness and swelling around the eyes—signs of a bacterial disease (Mycoplasma gallisepticum) that first appeared in 1994 and is now found in House Finch populations from coast to coast.

The eyes of this female House Finch are swollen by disease. Photo by Dan Fleming.
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This special push to track both sick and healthy House Finches is being carried out through the Cornell Lab’s Project FeederWatch, an annual winter survey of feeder birds that runs from November through April. New participants are invited to sign up to help at Making the correct ID is important, so there’s additional help provided in distinguishing among similar species, such as the Purple Finch and Cassin’s Finch.

“House finches are providing a unique window into disease dynamics,” says Wesley Hochachka, Assistant Director of Bird Populations Studies at the Cornell Lab of Ornithology. “We want to understand how this disease is spreading, if cases are more or less severe than they used to be, and how the birds’ immune systems are adapting to fight this threat.” Though this disease does not affect people, understanding how it’s transmitted provides insight into how human diseases are spread.

House Finch eye disease first appeared in the eastern United States and arrived in parts of the West in 2003. There is evidence suggesting that western bacteria could cause more severe disease now than in the past.

“Collecting reports from western states is especially important because the disease is still spreading there,” says FeederWatch project leader Emma Greig. “We hope to encourage participation in states such as Utah, Colorado, and Nevada, because the data they provide are extremely valuable.”

To learn more about FeederWatch and to sign up, visit or call the Cornell Lab toll-free at (866) 989-2473. In return for the $15 fee ($12 for Cornell Lab members), participants receive the FeederWatcher Handbook and Instructions with tips on how to attract birds to your feeders, an identification poster of common feeder birds, and a calendar. Participants also receive Winter Bird Highlights, an annual summary of FeederWatch findings, plus the Cornell Lab’s quarterly newsletter. This year participants will also receive a coupon for  75-cents off a product from sponsor Bob’s Red Mill. One thousand new FeederWatchers will receive an additional coupon for a free Bob’s Red Mill product (up to $7.99 value).

Project FeederWatch is a joint research and education project of the Cornell Lab of Ornithology and Bird Studies Canada.


  • Williams

    Poor birds! I will definitely keep my eyes peeled, with all the feathered friends stopping by my yankee flipper squirrel proof bird feeder this fall and winter! Hope they all stay healthy.

  • Gayly Opem

    I have had house finches with the eye disease at my feeder in Racine, Wisconsin, first in 2012 and then again in 2013, but not for the 10 years preceding then. I used to have a feeder up for 12 months but now spend my winters in the South, so my feeder is only up from June to late October. In both years, the disease did not show up until the fall. In 2012, there were 3 or 4 finches that developed it. In 2013, only one finch showed signs by the time I left on Oct. 25. We have discussed this disease at meetings of the local Hoy Audubon Chapter. I do take down my feeder and clean it with bleach when I see diseased birds. My location is zip code 53402 if that is helpful.

  • Wendy Schrader

    We have many of these beutiful little birds at our feeders in far Northwest Illinois and have not seen this terrible eye disease in them. We have been avid bird watchers from our backyard feeders for many years.

  • Sampson

    I’d say the last 2 to 3 years my husband and I have noticed this illness in Finches. I mostly noticed House Finches with the disease about two and a half years ago. A summer ago, it seemed to be getting worse. As I counted several ill birds over the summer. I also noticed sick Lesser Goldfinches and Pine Siskins back then however not any now. All the Lesser Goldfinches look well presently and we haven’t had but Pine Siskins this year. Was I seeing things or has this disease spread to other Finch species??? I got a new feeder that supposedly spreads less disease being that it is not a tube feeder. I guess some experts think the birds eyes come in less contact with platform or lantern feeders than tube. I also use a 1 in 10 solution bleach water to clean the feeder whenever I see a sick bird. I have only seen 2 sick House Finches in the past few months(fall). One had a cyst under his eye that was quite large and without feathers. It suddenly got freezing(19 degrees) cold for three nights in a row and I haven’t seen him since. I hope the disease will die out or the birds get immune to this microbe. We live in the Southern Sierras.

  • Hugh

    Hi – Several other finch species in the family Fringillidae have been reported with House Finch eye disease. You can find a list among the FAQ on our Project FeederWatch eye disease page: – although this list may not be exhaustive. Thanks for the notes! – Hugh

  • Nancy Goddard

    This past late summer and fall, over a six week spread I found 17 dead finches around my home and feeders. I called the audobaun society but no one had any ideas except to wash and bleach feeders which I did. We have a lot of feeders and they were crowded more so than usual. We were filling up feeders almost every other day. Neighbor across the street also found a few dead finches. I thought perhaps it could have been this disease but never could bring myself to examining the dead bird so still do not know why. Thankfully it stopped.

  • RE

    I had one female house finch in Aug. with (I believe) avian pox. She had a large blister over one eye, but managed okay. House finches are year-round, daily, feeder visitors at my place in the Bay Area of California. I cleaned the birdbath with chlorine and wiped down feeders daily for a week or so. Saw her for several days, then no more. No other birds observed w/ disease. Are you interested in that, or just the conjunctivitis?

  • Meg Kolodick

    I’ve had house finches affecting over the past decade and participated in one study from Cornell, from 2007-2008. But, last summer, I had purple finches affected, too. One had the swollen eye, but another had scaly growths on one foot, that got bigger and bigger over the summer. Is this a different disease?

  • Joanne Loveridge

    I live in Saskatchewan, Canada and I first noticed the house finch eye disease last year. I had one finch that had a pretty severe case of avian pox. His one eye had scaly patches around his eye. He didn’t look like he could see out of it very well. I also had a couple of finches this year with the swelling around the eye. They didn’t appear as bad as the finch I had last year as there wasn’t the scaling only what looked like some swelling.

  • Sampson

    Hello Project Feeder Watch Bird Lovers,
    After coming back from a lengthy vacation over the holidays the birds seemed to be disease free. However, after about 2 weeks of feeding Black Oil Sunflower seeds one showed up. It is a male House Finch with a horrible unsightly black unfeathered tumor between his eyes. I think it is avian pox. It is so large that he can’t see well. He is also acting unusually aggressive to all other birds. Also, when he lands on a rock he seems to go in circles. I’m hoping he will go away or pass on before infecting other birds. In the mean time, I’m bleaching the feeder often and cleaning out the birdbath.

  • A House Finch with conjunctivitis (I’m pretty sure) showed up in our yard on Gabriola Island in BC a few days ago. He’s been sitting at the hummer feeder, cleaning up the bugs and spilled juice, I suppose. Does he pose any threat to the hummers’ health?

  • Annie Sampson

    I believe the eye disease is only contagious to other finches or the frigillidae family. However, There is another disease called avian pox that can jump species which manifests itself by tumors on birds but I’m not sure if necessarily to hummers. I’ve seen both diseases here in the southern sierras on finches. I would suggest cleaning the feeder with 1 in 10 solution bleach to water then thoroughly rinse with water even though normally I clean the hummer feeder with just vinegar then rinse well. I also do this if I see any sick birds on my seed feeder and spray the same bleach solution in my bird bath then rinse thoroughly if I notice a sick bird drinking from it. Hope this helps…

  • Thanks Annie. The hummer feeders get cleaned and filled daily (we have zillions of Rufous here right now) although not with bleach. I’ll do that today. Will also clean the birdbaths with the bleach solution as long as the finch (which I’m pretty sure has conjunctivitis, not pox) is here.

  • Hugh

    Hi Sharon – thanks for asking, and thanks to Annie for the good advice on feeder maintenance. We checked with one of our House Finch eye disease researchers, Wesley Hochachka. He said that there is very little risk to your hummingbirds. “The strain of bacteria that causes disease in House Finches is very specific to House Finches, at least insofar as infections cause a severe disease,” he said. “We have been finding that many other species of birds are getting exposed to this bacterium, but for whatever reason other species, even other species of finches, have immune systems that are able to cope easily with infections by the very same bacteria would cause disease in House Finches. Hummingbirds are so distantly related to finches that I would expect the bacteria from House Finches not to cause any harm to hummingbirds.” Hope this helps ease your mind! – Hugh

  • Good news! Thanks so much Hugh.

  • Annie Sampson

    You are welcome Sharon…I know that I would be worried too about the little flying jewels.

  • Annie Sampson

    You are welcome Hugh. I wish this disease could be shut down and stop hurting the Finch populations. I have noticed it on a Lesser Goldfinch or perhaps it could have been avian pox which can show up on their faces. Here in the southern sierras at about 4,500 ft elevation we get the tiny Lesser Goldfinch, House Finch, and their big cousin the Black Headed Grosbeak(which thank God I’ve never seen any sign of disease).

  • Mike Mason

    I saw a female finch on my feeder last week that apparently had this infection. One eye was totally swollen shut and looked very infected. We saw the same bird, or perhaps a different one the following days. Will definitely be cleaning my feeders.

  • Gayly Opem

    I live along Lake Michigan in Caledonia, Wisconsin 53402. I had house finches at my feeder last year with the eye disease but so far this year, none have appeared. However, I have cardinals that has some type of disease, both last year and this year. They lose their feathers, usually starting on th head so there is no crest. Last year, I had a male like that and this year, a male and female. The female seems to have developed the condition in the last few weeks, the male earlier. It is very sad to see such regal birds looking so poorly. Do you know what this might be?

  • Sampson

    Hi Gayly,
    I believe these symptoms are from avian pox. I have seen tumors and places on birds that are featherless. However,they are House Finches where I live. We don’t have Cardinals here in the Southern Sierras however, I wish we did. I would suggest cleaning the birdbath with 10% bleach/water and the feeder too. Just spray on leave for 10 minutes or so then rinse with water. It’s not full proof since they obviously can make contact with with each other away from the feeders but I’m told it helps.

  • Regina

    During this weekend’s feeder watch, I observed a tufted titmouse missing its left eye. There did not appear to be any swelling, tumors or growths on other parts of the body. The area around the missing eye was ‘messy’ looking, the way the feathers of infected house finches sometimes appear. From what I’ve read about House Finch Eye Disease, it seems unlikely this titmouse has conjunctivitis, but may actually be the victim of avian pox. Is this correct? In either case, a thorough cleaning of the feeders is warranted, and I will continue to monitor this individual as long as it frequents the area.

  • Hui

    Four House Finches came to our feeders late this afternoon, and one of these was a female House Finch with conjunctivitis in her left eye (it had basically swollen her eye to the point that you could not see the eye at all). She was still able to feed as her right eye appeared healthy. Very sad to see this.

    I have recently given all the feeders a good cleaning, but will do so once again.

    From Delta, British Columbia, (Western) Canada.

  • Jack VanDyk

    Over the last few years I also observed House finches with conjunctivitis on our feeders, indeed sad to see.
    I have seen Gold finches too with both eyes affected. Three winters back when we had an irruption year with a lot of Pine Siskins and Common Redpolls, several of these birds were effected too.
    I am not sure of this all was from conjunctivitis or avian pox. All I remember that all these birds did have swollen eyes, and we’re constantly feeding..
    I do have many birds in my yard and feed them all year long. Will clean feeders again too.
    From Vernon British Columbia Canada.

  • Anita Kennedy

    This year is the first year that I have observed the Purple finches with what I think is conjunctivitis, the birds’eye was almost swollen shut and it kept wiping both eyes. I have seen a couple more with the disease, but not sure which disease it was. I will clean feeders at once.

    From southwest MO

  • Since about the second week of March I began to find dead Pine Siskins. To date there have been 6 or 7. I have a couple of feeders with sunflower meats and the Siskins have been a ravishing horde emptying them every day. At first I noticed that one or 2 that wouldn’t fly away when we approached. Shortly afterwards I began to find dead birds. I took the feeders down and cleaned them with water and diluted bleach. I kept them down for a week hoping the Siskins would move on. I’ve since read that they are susceptible to salmonella. I’m keeping the feeders and the bird bath clean. The ravishing hordes of Siskins are still around. I’m ready for them to go home so the others birds have a chance at the feeders…well, then the Gold Finches would be the major horde. How can I complain?

  • Andree Dubreuil

    For the last 15 days ,, I have been a Lucky,, bird observer,, and if I may note,, not one of my observations was entered nor registered in E-Bird,, to see GALLUPUS OF HUNDREDS OF cOMMON rEDPOLLS,, IS UNIQUE,,
    Many of my observations and pictures have been sent to Bird Studies Canada.. hundreds of Common Redpolls..
    For all of you,, who feed them,, I sincerely greet you..
    and perhaps our mentions of them kept secret.. But.. as I sit in front of my patio Windows,, with the wonderful stickers,, which avoid,, and stunnings,, I must admit.. this
    and the many moments of their migration flight,, and the wonderful support of all the backyard birders..
    Greetings.. and your seeds, pictures, patience,, is a reward to me.. as ,, I know,, you are there for them..
    I gratefully thank you
    Andree Dubreuil, Trois-Rivières, Québec, Canada

    [This comment has been migrated from an earlier post version by Cornell Lab staff.]

  • tiffany

    I have a bird here in southern Illinois I’ve never seen. Trying to figure out what it is. Can’t seem to get a picture to upload tho.

    [This comment has been migrated from an earlier post version by Cornell Lab staff.]

Help Us Track Sick Birds With Project FeederWatch