House Finch Disease Survey

House finch with eye disease©Janet Allen House finch with eye disease

NOTE: House Finch Disease Survey no longer is operating, but when we participate in Project FeederWatch or some other projects, there's a space to indicate whether any of the finches we observed had House Finch Disease.

House Finch eye disease is a form of conjunctivitis caused by a bacterium known as Mycoplasma gallisepticum. Tracking this disease helped scientists better understand the disease process in general, not just as it has affected bird populations.

Despite its name, I've seen goldfinches with the disease as well as one house sparrow that also appeared to have the disease.

As of April 2011, I had still noticed house finches with the disease. For the past few years, though, I haven't seen any birds with the disease. BUT I have seen fewer house finches—probably not a coincidence since the disease probably cut the population down.

Goldfinch with eye disease ©Janet Allen Goldfinch with eye disease

For a long time, I didn't see any house finches, goldfinches or other birds that appeared to have the disease. I still submitted my results, though, since knowing about the absence of birds or of birds with disease is just as valuable information as knowing how many birds are affected.

After years of recording healthy birds, I found some birds with the disease starting in the 2004-2005 season. I have to admit I was beginning to wonder whether it was worth bothering with this project after so many years of never seeing the disease, but now that the disease is in my area, I'm glad I had been submitting the data. I suspect that these positive disease findings are much more valuable against the backdrop of all those negative results than it would have been otherwise.