Lyme disease is largely being spread by birds, according to research by a team from the School of Public Health. The team analyzed data on 71 species of birds that carry the black legged tick which is known to be a major carrier of Lyme disease. The journal Frontiers in Ecology and the Environment reports that almost 60 percent of the bird species can infect ticks with the bacterium that causes Lyme disease.
It was previously known that birds could be carriers. However up until now it was thought that the worst offenders were mammals like chipmunks, mice and shrews.
"But the study shows that the expansion of the range of Lyme disease in the Northeast and Midwest over the past 20 to 30 years can also be attributed to birds, she said. For example, nearly 70 percent of brown thrashers, a ground-dwelling species, carried the tick, post-doctoral researcher and main author Robert Brinkerhoff said."
http://lymehandbook.com/2010/01/13/birds-spread-lyme-disease