BirdAnalyst
BBS Route · Colorado · BCR 10

Great Divide Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 89 species recorded across 46 survey years, still active.

89Species RecordedSpecies recordedDistinct species detected on standard-protocol BBS runs here across all years on record — a measure of survey breadth, not a complete checklist.Full methodology →
46Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1974–2024Span
9Observers

Bird Species Found on Colorado Great Divide

Top 40 of 89 species by most recent count. Each links to its species trend.

Species recorded on the Great Divide route.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →History
Brewer's SparrowPasserellidae842024-23%1976
Vesper SparrowPasserellidae622024+71%1976
Western MeadowlarkIcteridae612024+418%1976
Mourning DoveColumbidae502024-31%1976
Sage ThrasherMimidae372024+2%1976
Horned LarkAlaudidae332024+34%1976
Green-tailed TowheePasserellidae212024+46%1976
Brewer's BlackbirdIcteridae112024-64%1976
American RobinTurdidae112024+557%1976
American CootRallidae112015n/an/a
Cliff SwallowHirundinidae82008+120%1989
Canada GooseAnatidae82023+700%2014
European StarlingSturnidae72024-20%1976
Brown-headed CowbirdIcteridae72024+108%1977
Common RavenCorvidae62024+50%2007
Red-tailed HawkAccipitridae42024+80%1981
Clay-colored SparrowPasserellidae41977n/an/a
Sharp-tailed GrousePhasianidae42024-33%2012
Northern HarrierAccipitridae32024+133%1978
Tree SwallowHirundinidae32023+175%1989
Mountain BluebirdTurdidae32019+100%1981
Fox SparrowPasserellidae31977n/an/a
Blue-gray GnatcatcherPolioptilidae32019+75%1984
Gray FlycatcherTyrannidae32012+200%1998
Pied-billed GrebePodicipedidae32016+200%2014
Short-eared OwlStrigidae32024+200%2015
Red-winged BlackbirdIcteridae22024-36%1976
Barn SwallowHirundinidae22024+17%1976
MallardAnatidae22024-60%1977
American CrowCorvidae22019+50%2015
Lark SparrowPasserellidae22024-8%2001
Swainson's HawkAccipitridae22024+100%1981
Wilson's SnipeScolopacidae22022+67%1986
Eastern KingbirdTyrannidae21982n/an/a
Northern PintailAnatidae21984n/an/a
Rock PigeonColumbidae22008+100%1986
Great Horned OwlStrigidae22024+33%1991
American GoldfinchFringillidae22022+33%1995
Common PoorwillCaprimulgidae22022-25%2011
Loggerhead ShrikeLaniidae22018+100%2010

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. A route is a sample, not a census.