BirdAnalyst
BBS Route · Colorado · BCR 16

Rollins Pass Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 77 species recorded across 22 survey years, still active.

77Species 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 →
22Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1998–2025Span
4Observers

Bird Species Found on Colorado Rollins Pass

Top 40 of 77 species by most recent count. Each links to its species trend.

Species recorded on the Rollins Pass 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
Broad-tailed HummingbirdTrochilidae232025+17%2001
American RobinTurdidae192025-15%2001
Ruby-crowned KingletRegulidae122025-46%2001
Hermit ThrushTurdidae112025-51%2001
Brewer's BlackbirdIcteridae92014+800%2008
White-crowned SparrowPasserellidae72025-78%2001
Pine SiskinFringillidae62025-81%2001
Warbling VireoVireonidae62025-45%2001
Mountain ChickadeeParidae62025-68%2001
Clark's NutcrackerCorvidae52025-36%2001
Black-capped ChickadeeParidae52025-30%2004
Violet-green SwallowHirundinidae52025+367%2002
American CrowCorvidae52025+138%2003
Black-billed MagpieCorvidae42021+114%2007
Red CrossbillFringillidae42025+357%2003
Tree SwallowHirundinidae42025-66%2001
Mourning DoveColumbidae42007+100%2002
Canada GooseAnatidae42010n/an/a
Cassin's FinchFringillidae32025+100%2002
Band-tailed PigeonColumbidae32001n/an/a
Dusky FlycatcherTyrannidae32025+0%2004
Western Wood-PeweeTyrannidae22025-56%2001
Savannah SparrowPasserellidae21998n/an/a
Lincoln's SparrowPasserellidae22025-77%2001
MacGillivray's WarblerParulidae22025+0%2001
Northern House WrenTroglodytidae22025+14%2002
Golden-crowned KingletRegulidae22015+167%2003
Mountain BluebirdTurdidae22021+400%2002
Olive-sided FlycatcherTyrannidae22022+50%2006
Hairy WoodpeckerPicidae22022+0%2014
Red-naped SapsuckerPicidae22025+0%2015
Spotted TowheePasserellidae22021+100%2019
Wild TurkeyPhasianidae22025n/an/a
MallardAnatidae11998n/an/a
Wilson's SnipeScolopacidae12006+0%1998
Steller's JayCorvidae12025+71%2003
Common RavenCorvidae12025-46%2001
Brown-headed CowbirdIcteridae12025+67%2001
Pine GrosbeakFringillidae12018-33%2004
Chipping SparrowPasserellidae12025-57%2001

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