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Species · Colorado · BBS 2026 Release · 1966–2025

Ash-throated Flycatcher Population Trend in Colorado

All statesAerial insectivores

Ash-throated Flycatcher in Colorado has surged: up 900% on the route-weighted index since 1972.

+900%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 →
61Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Ash-throated Flycatcher 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Ash-throated Flycatcher has surged in Colorado: up 900% on the route-weighted index since 1972.

Ash-throated Flycatcher Population Forecast in Colorado

If the recent trend holds, Ash-throated Flycatcher in Colorado is projected to rise about 16% by 2030 — from 1.5 in 2025 to a central estimate of 1.7 (95% range 1.2–2.2). A 5-year backtest shows a typical error of ±18.3%, with 100% of held-out values landing inside the 95% band.

+16%Change by 2030TrendPercent 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 →
1.7Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
1.2–2.295% 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 →
±18.3%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, Ash-throated Flycatcher in Colorado is projected to rise about 16% by 2030 — from 1.5 in 2025 to a central estimate of 1.7 (95% range 1.2–2.2). A 5-year backtest shows a typical error of ±18.3%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20261.61.12.1
20271.61.12.1
20281.61.22.1
20291.71.22.2
20301.71.22.2

Ash-throated Flycatcher Survey Routes in Colorado

Routes recording Ash-throated Flycatcher 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 →
Walsenburg3120251995
Baxter Pass2320241995
Douglas Pass2120241982
Cokedale1420251995
Wray Gulch1220251988
Rosevale1120252009
Mesaverde Np1020251996
Animas1020041996
De Beque1020251992
Angora920251998
Delta720211973
Browns Park720251992
Nucla720251999
Black Sulphur Cr620252015
Trinchera520252005
Falfa420251971
Paonia420251993
Rifle Falls420251998
Doyle Bridge 2320232001
Animas 2320252005
Basin320251996
Timpas320131995
Gardner320251998
Ludlow320252001
Maybell220251992

Ash-throated Flycatcher Population Trend in Other States

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Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.