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Species · Washington · BBS 2026 Release · 1966–2025

Olive-sided Flycatcher Population Trend in Washington

All statesAerial insectivores

Olive-sided Flycatcher in Washington has fallen sharply: down 55% on the route-weighted index since 1970.

-55%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 →
76Routes 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 →
57YearsYears 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 WashingtonNotable 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 declinecomputed 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 →

Olive-sided Flycatcher has fallen sharply in Washington: down 55% on the route-weighted index since 1970.

Olive-sided Flycatcher Population Forecast in Washington

If the recent trend holds, Olive-sided Flycatcher in Washington is projected to fall about 76% by 2030 — from 1.8 in 2025 to a central estimate of 0.45 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±69.5%, with 80% of held-out values landing inside the 95% band.

-76%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 →
0.45Projected 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 →
0.00–1.795% 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 →
±69.5%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 Washington is projected to fall about 76% by 2030 — from 1.8 in 2025 to a central estimate of 0.45 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±69.5%, with 80% 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 →
20260.630.001.9
20270.580.001.9
20280.540.001.8
20290.490.001.8
20300.450.001.7

Olive-sided Flycatcher Survey Routes in Washington

Routes recording Olive-sided Flycatcher in Washington.
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 →
Hurricane Rg1720251992
Ilwaco1620251975
Deer Park1420062002
Vashon Is.1020251995
Warm Beach820171968
E. Mt. Adams620251995
Camas620091977
Port Angeles420251970
Rimrock420251968
Mcchord420151996
Raymond 2420242022
Ronald420251973
Spring Lake420251982
Deception420181992
Snowden320251971
Cusick320251982
Mazama320221993
Mukilteo320251993
Yakima319961996
Cloverland320251993
Warm Beach 2320242018
Carnation320241989
Newhalem220251969
Montesand220241992
Keller219831968

Olive-sided Flycatcher Population Trend in Other States

alaskaarizonacaliforniacoloradoidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniasouth-dakotautahvermontwest-virginiawisconsinwyoming

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