House Finch deformity

I shot this poor guy this morning at my feeder. He was feeding ok, but I have to wonder how he will fare in the long run? I've seen a number of these bill deformities over the years, what is the cause?

Dan Brown

These poor birds sure do get the bad stuff, don't they? Last year almost every one of them at my feeders had horrible problems with their eyes. I later read online that it was a disease that was running rampant through their breed. Perhaps this is this year's disease???

I'm just starting to see these back at my feeders again so I'll keep an eye out to see how they are doing this year. I really hope this is just a one time thing we're seeing here and not another avian disease.

Poor guy. I've seen images of birds of birds with bill deformaties but none like this. Julie, yes, I've read that house finches and other birds are susceptible to conjunctivitis. They can pass it to one another quite easily. People who have feeders clean them thoroughly if they see a bird visit with this. I understand sometimes they'll even take the feeder down temporarily because of this.

I think this is a one-off. One hypothesis is that the bird was hatched without an upper mandible, somehow lost it or it did not develop properly. This allows the bottom mandible to grow freely because it does not have a top mandible to rub against and wear down. I had a budgie with a problem similar to this and I had to file the beak to keep it from growing.

There are a couple of diseases that affect feeder finches like House Finches, Goldfinches, Purple Finches and Redpolls. One is Salmonella and the other is Mycoplasma. We have had the latter this spring in the Maritimes as evidenced by reports of a few birds with gummed-up eyes (conjunctivitis). One way to reduce the prevalence of these diseases is to regularly wash your feeders with warm soapy water and disinfect with a mild solution of bleach and water.