BirdAnalyst
BBS Route · Colorado · BCR 10

Great Divide Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 91 species recorded across 47 survey years, still active.

91Species 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 →
47Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1974–2025Span
9Observers

Bird Species Found on Colorado Great Divide

Top 40 of 91 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 SparrowPasserellidae822025-20%1976
Vesper SparrowPasserellidae692025+68%1976
Western MeadowlarkIcteridae632025+314%1976
Mourning DoveColumbidae462025-34%1976
Horned LarkAlaudidae312025+38%1976
Sage ThrasherMimidae272025-4%1976
Green-tailed TowheePasserellidae262025+57%1976
Brewer's BlackbirdIcteridae142025-49%1976
Greater Sage-GrousePhasianidae142025+236%1978
American RobinTurdidae112025+471%1976
American CootRallidae112015n/an/a
Common RavenCorvidae102025+140%2007
Brown-headed CowbirdIcteridae82025+85%1977
Cliff SwallowHirundinidae82008+120%1989
Red-tailed HawkAccipitridae72025+140%1981
Northern HarrierAccipitridae52025+267%1978
Canada GooseAnatidae52025+400%2014
European StarlingSturnidae42025-25%1976
Clay-colored SparrowPasserellidae41977n/an/a
Sharp-tailed GrousePhasianidae42024-33%2012
House SparrowPasseridae42025n/an/a
Black-billed MagpieCorvidae32025-75%1976
Tree SwallowHirundinidae32023+175%1989
Fox SparrowPasserellidae31977n/an/a
Blue-gray GnatcatcherPolioptilidae32019+75%1984
Gray FlycatcherTyrannidae32012+200%1998
Pied-billed GrebePodicipedidae32016+200%2014
Short-eared OwlStrigidae32024+200%2015
Eurasian Collared-DoveColumbidae32025-14%2017
Golden EagleAccipitridae22025+33%1976
Say's PhoebeTyrannidae22025+50%1977
Red-winged BlackbirdIcteridae22025-55%1976
Barn SwallowHirundinidae22025+0%1976
MallardAnatidae22025-65%1977
American CrowCorvidae22019+50%2015
Lark SparrowPasserellidae22025-73%2001
Swainson's HawkAccipitridae22025+40%1981
Lark BuntingPasserellidae22025-63%1985
Bullock's OrioleIcteridae22025-33%1985
Wilson's SnipeScolopacidae22022+67%1986

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. A route is a sample, not a census.