North American Breeding Bird Survey – Get Involved in Colorado!
David Suddjian
Breeding Bird Survey Colorado State Coordinator
It’s about half an hour before sunrise, as you stand beside your car on a quiet rural road. The eastern sky is lightening and birds are singing. You have just begun your first three-minute-long point count at stop #1 of your Breeding Bird Survey route – the first of 50 stops you will visit today. Lark Bunting is singing, three Horned Larks larking, Mourning Dove, Western Meadowlarks, a pair of Western Kingbirds, and there’s a Say’s Phoebe calling near that farmhouse. It is going to be another fun survey!
Thus begins one person’s volunteer effort for the North American Breeding Bird Survey (BBS). The BBS is a long-term, large-scale, international avian monitoring program initiated in 1966 to track the status and trends of North American bird populations. The BBS was created to monitor bird populations over large geographic areas in response to concerns about how pesticides like DDT were affecting bird populations. Although many concerns over pesticide use in North America have subsided, bird populations continue to be subjected to numerous threats including habitat loss, habitat fragmentation, climate change, land-use changes, and other chemical contaminants. Today, the BBS continues to monitor bird populations across North America and informs researchers and wildlife managers of significant changes in bird population levels.
Each year during the height of the avian breeding season (late May to early July), skilled birders collect bird population data along roadside survey routes. Each survey route is 24.5 miles long with stops situated 0.5-mile apart. At each stop, a 3-minute point count is conducted and every bird seen or heard within a 0.25-mile radius is recorded. Routes are surveyed once each season, following the same roads and making the same stops each year. Over 4100 survey routes in the continental U.S. and Canada provide an index of population abundance that is used to estimate population trends and relative abundances at various geographic scales.
Colorado hosts 136 BBS survey routes distributed across all areas of the state, and reaching all habitats. Many routes have faithful observers who have been covering them each year for many years. Other routes experience a natural turnover of observers, as one retires from the route and another birder picks it up. And some routes have not been surveyed at all for several years. In 2025, Colorado has 40 “vacant” routes (29%) that need skilled volunteer observers who can commit to adopting a route for at least three years.
Requirements for participation are:
(1) access to transportation to complete a survey,
(2) good hearing and eyesight, and
(3) the ability to identify all breeding birds in the area by sight and sound. Knowledge of bird songs and calls is extremely important because most birds counted on the surveys are detected by sound.
A BBS survey requires about five hours to complete, plus travel to and from the route location.
Can you volunteer to adopt a survey route so Colorado can continue to have good coverage for this important and longest-running continent-wide breeding bird monitoring program? If you would like to volunteer for a route or have any questions, please contact state coordinator David Suddjian dsuddjian@gmail.com to get started.