About the Data What do FeederWatch data tell us? When thousands of FeederWatchers in communities across North America count birds and send their tallies to the FeederWatch database, the result is a treasure trove of numbers, which FeederWatch scientists analyze to draw a picture of winter bird abundance and distribution. FeederWatch data show which bird species visit feeders at thousands of locations across the continent every winter. The data also indicate how many individuals of each species are seen. This information can be used to measure changes in the winter ranges and abundances of bird species over time. Why are FeederWatch data important? With each season, FeederWatch increases in importance as a unique monitoring tool for more than 100 bird species that winter in North America. What sets FeederWatch apart from other monitoring programs is the detailed picture that FeederWatch data provide about weekly changes in bird distribution and abundance across the United States and Canada. Importantly, FeederWatch data tell us where birds are as well as where they are not. This crucial information enables scientists to piece together the most accurate population maps. Because FeederWatchers count the number of individuals of each species they see several times throughout the winter, FeederWatch data are extremely powerful for detecting and explaining gradual changes in the wintering ranges of many species. In short, FeederWatch data are important because they provide information about bird population biology that cannot be detected by any other available method. How do scientists know when a species is at risk? Population sizes of many species vary from year to year. Downward trends for two, three, or even more years may not indicate actual population declines; in fact, such trends may simply reflect short-term weather patterns or other variations in natural food supply and abundance. Sometimes, however, the data reveal a long-term population decline of a particular species. When bird population scientists become aware of such a trend, they evaluate what they know about the species, its habitat, and other factors that may be causing its decline. For example, is the species’ food in short supply? Has the amount of suitable habitat changed on the species’ breeding or wintering grounds? Has a potentially competitive species shown a population increase? For example, FeederWatch data from Florida showed that the winter population of the Painted Bunting declined steadily since the 1980s. This information, combined with complementary data from the Breeding Bird Survey (showing that breeding populations of Painted Buntings have declined at a rate of about 4 percent per year) led the Florida Game and Fresh Water Fish Commission to begin a systematic monitoring program of bunting populations so they could learn how to protect them. So, by combining all they know about a species from monitoring data and intensive research projects, scientists can begin to understand why a species is declining, and to make recommendations for its recovery before it is too late. How are FeederWatch data used? Project FeederWatch data are used to document and understand the distribution and abundance of birds that visit feeders in North America. In 2017 to celebrate the 30th anniversary of Project FeederWatch, the Cornell Lab’s Living Bird magazine published an article highlighting some of the things researchers have learned from FeederWatch data over the years. The massive amounts of data collected by FeederWatchers across the continent help scientists understand long-term trends in bird distribution and abundance the timing and extent of winter irruptions of winter finches and other species. expansions or contractions in the winter ranges of feeder birds the kinds of foods and environmental factors that attract birds how disease is spread among birds that visit feeders FeederWatch information and results are regularly published in Scientific Journals The Condor The Proceedings of the National Academy of Sciences Regional Birding, Garden, and Nature Newsletters Living Bird News, newsletter of the Cornell Lab of Ornithology BirdWatch Canada, newsletter of Birds Canada National Magazines Audubon Magazine Birder’s World BirdWatcher’s Digest Birds and Blooms Newspapers nationwide FeederWatch data were used for a book about backyard birds called Birds at Your Feeder. Sample pages of the book can be seen on Google Books. FeederWatch data are also used to help Project FeederWatch participants and Lab of Ornithology members learn more about feeder birds through the project’s annual publication, Winter Bird Highlights, which reports results from each season.