BirdAnalyst
BBS Route · Colorado · BCR 16

South Fork Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 85 species recorded across 21 survey years, still active.

85Species 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 →
21Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1994–2025Span
5Observers

Bird Species Found on Colorado South Fork

Top 40 of 85 species by most recent count. Each links to its species trend.

Species recorded on the South Fork 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
Cliff SwallowHirundinidae1082002+800%1999
American RobinTurdidae432025-20%1997
Ruby-crowned KingletRegulidae402025-22%1997
Western TanagerCardinalidae252025-3%1999
Violet-green SwallowHirundinidae222025-24%1997
Canada GooseAnatidae202025+440%2014
Warbling VireoVireonidae142025-28%1997
Hermit ThrushTurdidae122025-18%1997
Chipping SparrowPasserellidae102025-17%1997
Pine SiskinFringillidae82025-84%1997
Clark's NutcrackerCorvidae82025-16%1999
Canada JayCorvidae72025+8%1999
American CrowCorvidae72025+127%2008
Green-winged TealAnatidae62025+500%1994
Green-tailed TowheePasserellidae62025+133%1997
Lincoln's SparrowPasserellidae52025-59%1999
Red-breasted NuthatchSittidae52025+150%2001
Broad-tailed HummingbirdTrochilidae42025-52%1997
Western Wood-PeweeTyrannidae42025-48%1997
Steller's JayCorvidae42025-44%1997
Cassin's FinchFringillidae42025-36%1997
White-crowned SparrowPasserellidae42025-25%1997
Tree SwallowHirundinidae42025-70%2001
Common MerganserAnatidae32025-33%2002
Common NighthawkCaprimulgidae32024+100%1999
Olive-sided FlycatcherTyrannidae32024-50%1999
Pine GrosbeakFringillidae32024+13%1997
Northern House WrenTroglodytidae32025-22%1997
Common RavenCorvidae32025-67%2002
Long-eared OwlStrigidae32021+200%2017
MallardAnatidae22025-67%2002
Dusky FlycatcherTyrannidae22013+80%2001
Black-billed MagpieCorvidae22025+350%2003
Mountain BluebirdTurdidae22023-33%1999
Red CrossbillFringillidae22024-25%2001
Golden-crowned KingletRegulidae22024-38%2003
Downy WoodpeckerPicidae22025-55%2013
Savannah SparrowPasserellidae22017+100%2002
Great Horned OwlStrigidae22014n/an/a
Say's PhoebeTyrannidae22017+0%2014

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