To date, the House Finch eye disease has affected mainly the eastern House Finch population, which is largely separated from the western House Finch population by the Rocky Mountains. Until the 1940s, House Finches were found only in western North America. They were released to the wild in the East after pet stores stopped illegal sales of “Hollywood Finches,” as they were commonly known to the pet bird trade. The released birds successfully bred and spread rapidly throughout eastern North America. Since 2006, however, the disease has crossed the Rocky Mountains and started popping up in western states; the question now is, how much has it spread in the west?

Will Mycoplasma gallisepticum eventually cover the entire North American House Finch range? If so, at what rate will the epidemic continue to expand? Will House Finch numbers decrease in the West as they have in the East? Will other bird species become infected with the conjunctivitis? Data from Project FeederWatch participants will help us find out.



