Great Backyard Bird Count

National Audubon Society

Cornell Lab of Ornithology

Project name: Great Backyard Bird Count

Goals : Scientists and bird enthusiasts can learn a lot by knowing where the birds are. We want to take a snapshot of North American bird populations during late winter. These data can be combined with observations from other citizen-science projects, such as the Christmas Bird Count, Project FeederWatch, and eBird, to give us an immense picture of our winter birds.

Dataset summary : The Great Backyard Bird Count is an annual four-day event that engages bird watchers of all levels in counting birds and reporting their results to create a mid-winter snapshot of the numbers, kinds, and distribution of birds across the continent. Participants count birds for as little or as long as they wish during the four-day period and tally the highest number of birds of each species that they see at any one time. At the Great Backyard Bird Count web site, they fill out an online checklist to submit their counts. As the count progresses, anyone with Internet access can explore what is being reported from their own towns or anywhere in the United States and Canada. They can also see how the current year's numbers compare with those from any of the previous years. Participants may also send in photographs of the birds they see. A selection of images is posted in the GBBC online photo gallery. After the count, scientists analyze the results and post summaries highlighting the year's trends and findings. The Great Backyard Bird Count is managed by the Cornell Lab of Ornithology and Audubon, with sponsorship from Wild Birds Unlimited.

Year started : 1998

Season(s) and frequency : The GBBC takes place every year during 4 days around the second week of February

Frequency : Annually

Geographic area covered : North America (US and Canada)

Primary species covered : All species of birds

Field methods : Participants count the birds in their backyard, local park, or other natural area on one or all four count days. They can count in as many different locations as they wish, but they must keep separate records and fill out a checklist for each area. They watch the birds for at least 15 minutes on each day that they participate. It is recommended that they watch for a half-hour or more, so that they'll have a good sense of what birds are in their area. How to count: On the day(s) that they count, particpants watch their bird feeders or take a short walk (less than 1 mile) in their neighborhood or park. For each kind (species) of bird that they see, they keep track of the highest number of individuals that they observe at any one time. At the end of the day, checklists are submitted on the GBBC web site. Checklists include information about location, local habitat, count duration, and high counts for each species sighted on that day and location. Participants can submit one bird checklist for each day that they count or for each new area that they count in.

Sample size : In 2005, over 50,000 checklists were submitted from all 50 states and all but one Canadian province.