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Species · Colorado · BBS 2025 Release · 1966–2024

Dusky Flycatcher Population Trend in Colorado

All statesAerial insectivores

Dusky Flycatcher in Colorado has surged: up 557% on the route-weighted index since 1970.

+557%Since 1970TrendPercent 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 →
85Routes 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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Dusky 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 →

Dusky Flycatcher has surged in Colorado: up 557% on the route-weighted index since 1970.

Dusky Flycatcher Population Forecast in Colorado

If the recent trend holds, Dusky Flycatcher in Colorado is projected to rise about 28% by 2029 — from 2.6 in 2024 to a central estimate of 3.4 (95% range 2.5–4.2). A 5-year backtest shows a typical error of ±37.6%, with 40% of held-out values landing inside the 95% band.

+28%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 →
3.4Projected 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 →
2.5–4.295% 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 →
±37.6%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, Dusky Flycatcher in Colorado is projected to rise about 28% by 2029 — from 2.6 in 2024 to a central estimate of 3.4 (95% range 2.5–4.2). A 5-year backtest shows a typical error of ±37.6%, with 40% 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 →
20253.22.34.0
20263.22.44.1
20273.32.44.1
20283.32.54.2
20293.42.54.2

Dusky Flycatcher Survey Routes in Colorado

Routes recording Dusky 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 →
Mcphee Res.4720241996
Baxter Pass2420242013
Haycamp Mesa2120241998
Mesaverde Np2120241997
Lost Lake1220241990
Nucla1220242000
Powderhorn1120232008
Douglas Pass1020241985
Colona1020121983
Tincup1020241992
Marshall Pas1020081995
Black Sulphur Cr1020242015
Stillwater Pass 2720242010
Dolores Riv620241988
Radium620131998
Delta520211973
Willow Peak520211988
Pinon520241993
Cokedale520241995
Stillwater Pass520092009
Owl Creek Pass520241999
Weston Pass 2520242001
Cortez 2520172009
Maybell420192019
Yampa420231971

Dusky Flycatcher Population Trend in Other States

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