North American songbirds are vulnerable to a common, naturally occurring disease called mycoplasmal conjunctivitis, which causes red and swollen eyes. It’s a type of pinkeye, and sometimes it leads to blindness — which soon leads to death.
For the study, published this month in the Proceedings of the Royal Society B, researchers captured and put leg bands with electronic chips on 180 wild house finches around the Virginia Tech campus. Then they monitored the birds' activity around six nearby feeders over the winter of 2012-2013.
The data let them reconstruct the birds’ social networks — which ones associated with each other — as well as where they fed.
“We expected birds that were more central in the social network, or had more friends, to catch the disease, because previous research has found that this was important for accessing information about where food is located. But, we found instead that it was birds’ feeding preferences that were most important,” Damien Farine, a co-author of the study, said in an article published by the Virginia Tech News.
The birds that spent the most time at the feeders, rather than foraging in the wild, had the highest incidence of disease. They were the most “likely to be both a super-receiver and a super-spreader,” the study said.
So what can bird-loving humans do? Feeding birds in the winter months helps them survive harsh weather. But while doing so, you can fight off the disease-causing bacteria, the researchers say: Clean and disinfect the feeder every time you refill it.
