BirdAnalyst
Species · Colorado · BBS 2025 Release · 1966–2024

Olive-sided Flycatcher Population Trend in Colorado

All statesAerial insectivores

Olive-sided Flycatcher in Colorado has declined: down 40% on the route-weighted index since 1970.

-40%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 →
79Routes 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 Olive-sided 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 →

No notable trend signals for Olive-sided Flycatcher in Colorado. See the full index history below.

Olive-sided Flycatcher Population Forecast in Colorado

If the recent trend holds, Olive-sided Flycatcher in Colorado is projected to rise about 33% by 2029 — from 0.49 in 2024 to a central estimate of 0.66 (95% range 0.06–1.3). A 5-year backtest shows a typical error of ±35%, with 100% of held-out values landing inside the 95% band.

+33%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 →
0.66Projected 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 →
0.06–1.395% 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 →
±35%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, Olive-sided Flycatcher in Colorado is projected to rise about 33% by 2029 — from 0.49 in 2024 to a central estimate of 0.66 (95% range 0.06–1.3). A 5-year backtest shows a typical error of ±35%, with 100% 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 →
20250.650.051.3
20260.650.051.3
20270.660.051.3
20280.660.061.3
20290.660.061.3

Olive-sided Flycatcher Survey Routes in Colorado

Routes recording Olive-sided 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 →
Buffalo Park1020231992
Dolores919691969
Stillwater Pass720092002
Stillwater Pass 2720242010
Cheesman Lk620241969
Red Cliff620231989
Comanche Pk520241994
Ragged Mtn.520191994
Lost Lake420241994
Blackhead Pk420141991
Deadman Rd.420231992
Lake City 2420222016
Dolores Riv320241988
Tincup320241995
Powderhorn320232005
South Fork320241994
Radium320121998
Cochetopa Pass320242001
Heeney320192017
Gold Hill 2320232019
Buford220091980
Pagosa Spgs219821968
Willow Peak220181988
Tarryall220231988
Castleton220221988

Olive-sided Flycatcher Population Trend in Other States

alaskaarizonacaliforniaidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniasouth-dakotautahvermontwashingtonwest-virginiawisconsinwyoming

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