About the disease In the winter of 1994, Project FeederWatch participants in the Washington, D.C., area began reporting that House Finches at their feeders had swollen, red, crusty eyes. Lab tests revealed that the birds had Mycoplasma gallisepticum, a parasitic bacterium previously known to infect poultry. Mycoplasmal conjunctivitis, as the disease is sometimes called, spread rapidly across the Eastern Seaboard, leaving House Finches listless, mostly blind, and vulnerable to predators and bad weather. 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. Initially, House Finch eye disease primarily affected the eastern House Finch population, which is largely separated from the western House Finch population by the Rocky Mountains. In 2006, however, the disease was found west of the Rocky Mountains and has since spread to House Finch populations throughout the west.