OCTOBER 2000, ITHACA, N.Y. — Last winter was the warmest on record in 105 years. What did this mean for the birds? A continentwide network of "citizen scientists" helped researchers at the Cornell Lab of Ornithology find out. Now they're gearing up to find out what the birds will tell them this winter.

These "citizen scientists" are participating in Project FeederWatch, a winter-long (November through April) survey of birds that visit feeders throughout North America, sponsored by the Cornell Lab of Ornithology in partnership with Bird Studies Canada, National Audubon, and the Canadian Nature Federation. Started in 1987, the project has grown to more than 15,000 participants in the United States and Canada.

This year's summary of results contrasted bird abundances in the winter of 1999-2000 with the prior winter. Last winter, "FeederWatchers" reported an increase in "irruptive" species (birds that typically spend the winter in the North but periodically "irrupt" into more southerly regions, probably in response to low food availability farther north) east of the Rockies. Common Redpolls appeared in larger-than-average numbers even for an irruption year—larger than in any winter since 1994. They were especially abundant in a band stretching from the Northern Rockies to the North Atlantic region. FeederWatch data also show that Northern Shrikes invaded feeding stations across the northern tier last winter. Nicknamed "butcher birds" for their technique of impaling their prey on thorns and branches, shrikes showed up at many feeding stations to catch songbirds, presumably because of lower numbers of small rodents in the fields where they typically hunt. Last winter's FeederWatch data also indicated a scarcity in ground-feeding birds such as Harris's Sparrows. The lower abundances were especially notable in the Mid- and South-Central regions, where it may be related to drought. Most ground-feeding species rely on seeds produced by smaller plants (grasses and forbes); production of these seeds can be easily affected by rainfall-or a lack of it.

FeederWatchers have also helped make some interesting discoveries based on the long-term data. Findings published in the Canadian Journal of Zoology documented for the first time the cyclical changes in Varied Thrush abundance. FeederWatch data revealed that, on average, this species peaks in abundance every second year, perhaps in response to acorn availability in winter. Another discovery appeared in The Condor, a scientific journal published by the Cooper Ornithological Society. The data showed that although the Common Redpoll is an irruptive migrant probably forced south by lack of food, the redpolls' movements are like those of any other winter migrant when the birds irrupt southward. Findings such as these help scientists better understand the lives of bird species that would otherwise be a mystery because they live far to the north, in regions not typically covered by other monitoring programs.

FeederWatchers also play a critical role in tracking outbreaks of avian diseases. In 1994, Cornell Lab researchers asked FeederWatchers to help track the spread of a disease previously almost unknown in wild birds. This disease, called mycoplasmal conjunctivitis (often referred to as House Finch eye disease because it primarily hits House Finches) is manifested by symptoms including swollen, crusty eyes, which frequently lead to blindness and eventually death as the birds are caught by predators or eventually starve. In the prestigious Proceedings of the National Academy of Sciences, Lab researchers recently published a landmark paper about how this disease may have become the main factor regulating the abundance of House Finches. Starting this winter, Lab researchers are asking FeederWatchers to help with a newly expanded House Finch Disease Survey through which they hope to learn whether the disease has successfully crossed the Great Plains and started to infect House Finches in western North America.

"FeederWatchers are the eyes and ears for scientists studying North American feeder bird populations," says Wesley Hochachka, assistant director of the Cornell Lab's Bird Population Studies program and a coauthor of many FeederWatch-related scientific papers. "There's simply no other way to acquire data about continentwide populations throughout the entire winter. These data are critical in helping us understand both long- and short-term changes in bird populations and their environments."

One reason Project FeederWatch has been so successful is because it was designed with all of that in mind. "FeederWatch undergoes continuous evaluation and refinement by our staff scientists, some of whom are leaders in their fields," says Laura Kammermeier, FeederWatch project leader. "The materials are developed to educate participants before they even begin, and the data forms are carefully developed to prevent reporting errors and identification mistakes."

Another reason the project is a success, says Kammermeier, is because it's enjoyable, and participants learn a lot about the birds they so enjoy. "Although the protocol is scientifically rigorous, we've made it very easy for people of all ages, backgrounds, and skill levels to participate," she says. Many home schoolers use FeederWatch as an educational tool, and nature centers and bird clubs find that it is a great outreach vehicle.

Each fall, FeederWatchers await with great anticipation the unveiling of the "FeederWatch Top-10 List," the 10 most frequently reported species in North America. This year's list reads as follows: 10) House Sparrow, seen at 58 percent of feeders; 9) White-breasted Nuthatch, 65 percent of feeders-and a new Top-10 List species; 8) Black-capped Chickadee, 66 percent; 7) Northern Cardinal, 69 percent; 6) American Goldfinch, 72 percent; 5) and 4) House Finch and Blue Jay, both reported at 74 percent of feeders; 3) Downy Woodpecker, 75 percent; 2) Mourning Dove, 80 percent, and the species most frequently reported by FeederWatchers is; 1) Dark-eyed Junco, seen at 85 percent of FeederWatch feeders.

To sign up for Project FeederWatch, call the Cornell Lab at 800/843-2473 in the United States (in Canada, call Bird Studies Canada at 888/448-2473.) Sign up over the Web at <http://birds.cornell.edu/pfw/>. To sign up by check, send to PFW/Cornell Lab of Ornithology, P.O. Box 11 Ithaca, NY 14850.