When and where was it first noted?

Since January 1994, when House Finches with red, swollen eyes were first observed at feeders in the Washington, D.C. area, including parts of Maryland and Virginia, House Finch disease has spread rapidly through the eastern House Finch population. Mycoplasmal conjunctivitis, as the disease is commonly called, is caused by a unique strain of Mycoplasma gallisepticum, a parasitic bacterium previously known to infect only poultry.

Feeder Illustration by Julie Zickefoose

To date, the House Finch eye disease has affected mainly the eastern House Finch population (view a map showing prevalence of the disease since it was first observed), 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.

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? The House Finch Disease Survey will help us find out.

The results of your work and any updated information about the disease or the survey are published in our quarterly newsletter, Birdscope. Survey results are also printed in scientific journals such as the Proceedings of the National Academy of Sciences of the USA, the Journal of Wildlife Diseases and Emerging Infectious Diseases, a publication from the Center for Disease Control and Prevention.

Your observations are important.
Would you please help us track the spread of this harmful disease?


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