Bird-watching is not only about enjoying birds. It also is about gathering knowledge about them and contributing to their conservation.

I was especially reminded of this after we’d received two reports of house finches with diseased eyes in Bangor. The birds appeared to be blind, and were not seen again after initial sightings at feeders.

These reports are significant for two reasons. For one, it lets us know what is going on in wild bird populations. It also is an invaluable addition to an ongoing project, which has monitored what could be the same house finch eye disease first noticed during the winter of 1993-94.

It was during this time in Washington, D.C., that birders involved in the Cornell Lab of Ornithology’s “Project FeederWatch” began noticing house finches with crusty, swollen eyes. Reports from all over the eastern United States soon began pouring in to the lab. Scientists were able to determine the finches’ symptoms were caused by a new strain of bacterium that previously had only infected domestic poultry. They dubbed the disease mycoplasmal conjunctivitis.

Scientists compiled the data of finch populations to determine how badly the disease had affected them. The one thing that made this possible was the enthusiasm and concern of bird-watchers all over the continent. Through their efforts, a population of wild animals was monitored before, during, and after an outbreak – something that previously had been impossible to do.

So, the next time you see a bird – especially a house finch, although goldfinches also are susceptible – at your feeder, look closely. Your observations could contribute invaluably to the birds and to science.

If you’d like to become more involved, visit the National Audubon Society and Cornell Lab of Ornithology’s interactive web site at http://birdsource.cornell.edu. If you don’t have access to a computer, come to the Fields Pond Nature Center on Feb. 18 anytime between 1 and 3 p.m. Bring a list of birds seen at your feeder that morning or the day before, and Lee Snyder will enter the birds into Cornell’s database. You’ll see the ornithological maps of the U.S. change before your eyes.

Sightings:

15 evening grosbeaks, Fields Pond Nature Center; black-backed woodpecker, Jackman; snow buntings, Klatt Road, Hermon.

Chris Corio is a volunteer for Fields Pond Nature Center. Contact her at fieldspond@juno.com