Spread of Disease
Tracking the Spread of Disease in Wild Bird Populations
House Finch eye disease
In January 1994 House Finches with symptoms of an eye disease were
first observed at feeders near Washington, D.C. This "House Finch
disease" soon spread rapidly through the eastern House Finch population.
The map below shows the expansion of House Finch disease from 1994
through March of 1997, and was created using reports from participants
of the Lab of Ornithology's House Finch Disease Survey.
Map from Dhondt, A. A. 1998. "House Finch Eye Disease Heads Steadily West." BirdScope 12:11-12 Winter 1998.
Two of the goals of the House Finch Disease Survey are
- To track the spread of conjunctivitis in House Finches (as shown on the map) and other bird species such as American Goldfinches
- To detect any significant declines in House Finch populations.
Lab of Ornithology researchers asked the question "What proportion of birds at feeders have conjunctivitis?"
This graph shows the monthly prevalence (percentage) of conjunctivitis
in House Finches from three regions during the winter of 1997-98. We
see from the graph that the mid-Atlantic region consistently had the
highest percentage of sick finches.
Graph from Hartup, B. K. 1999."House Finch Disease 1997-98" Birdscope, 13: 7-12 Winter 1999.