BirdAnalyst
BBS Route · Colorado · BCR 16

Weston Pass Bird Survey Route

A standard 50-stop Breeding Bird Survey route. 73 species recorded across 7 survey years, no longer active.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 →
7Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →
1994–2000Span
2Observers

Bird Species Found on Colorado Weston Pass

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

Species recorded on the Weston 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
American RobinTurdidae382000+48%1996
Cliff SwallowHirundinidae322000-64%1999
Red-winged BlackbirdIcteridae272000+114%1996
Common RavenCorvidae262000+267%1996
Lincoln's SparrowPasserellidae252000+225%1996
Tree SwallowHirundinidae212000+486%1997
Pine SiskinFringillidae202000+600%1996
White-crowned SparrowPasserellidae192000-22%1996
Black-billed MagpieCorvidae172000+65%1996
Savannah SparrowPasserellidae172000+192%1996
Western MeadowlarkIcteridae162000+41%1996
Ruby-crowned KingletRegulidae142000+36%1996
Hermit ThrushTurdidae142000+186%1996
Broad-tailed HummingbirdTrochilidae112000+8%1996
Wilson's WarblerParulidae112000+86%1997
Yellow WarblerParulidae102000+86%1996
Brown-headed CowbirdIcteridae72000+400%1997
Mountain ChickadeeParidae72000+163%1997
Mountain BluebirdTurdidae62000+100%1996
Common GrackleIcteridae62000+500%1999
KilldeerCharadriidae52000+140%1996
Brewer's BlackbirdIcteridae51999+45%1996
GadwallAnatidae52000+150%1995
Northern House WrenTroglodytidae52000+80%1997
Green-tailed TowheePasserellidae52000+300%1997
Red-tailed HawkAccipitridae52000+400%1997
Horned LarkAlaudidae42000-33%1995
Steller's JayCorvidae42000+100%1998
Red CrossbillFringillidae41999+33%1995
Song SparrowPasserellidae42000+40%1997
Warbling VireoVireonidae42000+240%1998
MallardAnatidae32000+50%1995
Clark's NutcrackerCorvidae31999+250%1995
Vesper SparrowPasserellidae32000+0%1995
Fox SparrowPasserellidae32000+200%1994
Brewer's SparrowPasserellidae32000+25%1997
Ring-necked DuckAnatidae31999+0%1997
Dusky FlycatcherTyrannidae32000+200%1997
Green-winged TealAnatidae32000+0%1999
European StarlingSturnidae32000+0%1999

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