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Species · Colorado · BBS 2025 Release · 1966–2024

Cassin's Kingbird Population Trend in Colorado

All statesAerial insectivores

Cassin's Kingbird in Colorado has held roughly steady: down 8% on the route-weighted index since 1972.

-8%Since 1972TrendPercent 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 →
46Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cassin's Kingbird Trends in ColoradoNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Cassin's Kingbird in Colorado. See the full index history below.

Cassin's Kingbird Population Forecast in Colorado

If the recent trend holds, Cassin's Kingbird in Colorado is projected to fall about 51% by 2029 — from 1.1 in 2024 to a central estimate of 0.56 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±50.7%, with 80% of held-out values landing inside the 95% band.

-51%Change by 2029TrendPercent 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 →
0.56Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.295% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±50.7%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Cassin's Kingbird in Colorado is projected to fall about 51% by 2029 — from 1.1 in 2024 to a central estimate of 0.56 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±50.7%, with 80% of held-out values landing inside the 95% band.19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.570.001.2
20260.560.001.2
20270.560.001.2
20280.560.001.2
20290.560.001.2

Cassin's Kingbird Survey Routes in Colorado

Routes recording Cassin's Kingbird in Colorado.
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 →
Walsenburg3920241996
Cokedale2820241995
Mica Butte1419871968
Campo1320192018
Ludlow1020161998
Mesaverde Np620242009
Animas 2620212005
Edison619991989
Gribbles Prk620241998
Animas620041996
Falfa520241977
Gilpin520241979
Villegreen420241989
Dolores319721968
Doyleville319891989
Wet Mtns.320241999
Gardner320241999
Rush220241987
Hudson220032003
Doyle Bridge 2220191998
Adams Co.220222003
Crowley220221996
Trinchera220221990
Ellicott220241999
Timpas220191995

Cassin's Kingbird Population Trend in Other States

arizonacaliforniakansasmontananebraskanevadanew-mexicooklahomasouth-dakotatexasutahwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.