BirdAnalyst
BBS Route · Colorado · BCR 16

Stillwater Pass 2 Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 73 species recorded across 14 survey years, still active.

73Species 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 →
14Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
2010–2025Span
1Observers

Bird Species Found on Colorado Stillwater Pass 2

Top 40 of 73 species by most recent count. Each links to its species trend.

Species recorded on the Stillwater Pass 2 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
White-crowned SparrowPasserellidae772025+244%2012
American RobinTurdidae622025-24%2012
Lincoln's SparrowPasserellidae372025-8%2012
Pine SiskinFringillidae272025-48%2012
Song SparrowPasserellidae222025+80%2012
Broad-tailed HummingbirdTrochilidae202025-7%2012
Ruby-crowned KingletRegulidae192025-30%2012
Lazuli BuntingCardinalidae142025+111%2023
Mourning DoveColumbidae122025+283%2013
Yellow WarblerParulidae112025-27%2012
Spotted SandpiperScolopacidae102025+100%2012
Western Wood-PeweeTyrannidae102025-54%2012
Dusky FlycatcherTyrannidae102025-44%2012
Olive-sided FlycatcherTyrannidae92025+40%2012
Green-tailed TowheePasserellidae92025+154%2012
Hermit ThrushTurdidae72025-76%2012
Savannah SparrowPasserellidae62025-52%2012
Violet-green SwallowHirundinidae62025-70%2012
Mountain ChickadeeParidae62025+13%2012
Warbling VireoVireonidae52025-59%2012
Swainson's ThrushTurdidae52025-19%2013
Wilson's SnipeScolopacidae42025-20%2012
Brown-headed CowbirdIcteridae42025-46%2012
Red-winged BlackbirdIcteridae42025+38%2012
Red-breasted NuthatchSittidae42025+150%2017
Red-naped SapsuckerPicidae42025-40%2013
Great Blue HeronArdeidae42016-67%2012
Williamson's SapsuckerPicidae32025+125%2012
Red CrossbillFringillidae32023-54%2013
Chipping SparrowPasserellidae32025-29%2012
Western TanagerCardinalidae32025-55%2012
Barn SwallowHirundinidae32019-25%2013
American CrowCorvidae32025+0%2014
Black-billed MagpieCorvidae32025+67%2014
Hammond's FlycatcherTyrannidae22025-67%2012
European StarlingSturnidae22010n/an/a
Brewer's BlackbirdIcteridae22018-40%2011
Pine GrosbeakFringillidae22023+0%2012
Tree SwallowHirundinidae22025+0%2013
Wilson's WarblerParulidae22023-91%2012

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