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

Osprey Population Trend in Washington

All statesGeneralists

Osprey in Washington has surged: up 346% on the route-weighted index since 1972.

+346%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 →
70Routes 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 Osprey 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 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 →

Osprey has surged in Washington: up 345% on the route-weighted index since 1972.

Osprey Population Forecast in Washington

If the recent trend holds, Osprey in Washington is projected to rise about 46% by 2029 — from 0.35 in 2024 to a central estimate of 0.51 (95% range 0.35–0.67). A 5-year backtest shows a typical error of ±16.2%, with 100% of held-out values landing inside the 95% band.

+46%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 →
0.51Projected 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 →
0.35–0.6795% 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 →
±16.2%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, Osprey in Washington is projected to rise about 46% by 2029 — from 0.35 in 2024 to a central estimate of 0.51 (95% range 0.35–0.67). A 5-year backtest shows a typical error of ±16.2%, 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 →
20250.480.320.65
20260.490.330.65
20270.500.340.66
20280.510.340.67
20290.510.350.67

Osprey Survey Routes in Washington

Routes recording Osprey 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 →
South Elma420241984
Packwood420181983
Nighthawk420241993
Ewan320192004
Laurier320221998
Yakima320241993
Ozette220062006
Taholah220221990
Selah220162006
Deception219971992
Bunker Hill220221979
Cougar220231976
Asotin220242024
Everett220152015
Prescott220192019
Scootney Reservoir220232017
Horn Rapids220242006
Mukilteo220061994
Moses Coulee220152015
Rainier220162004
Vashon Is.220182004
Carnation220241988
Mendota 3220232006
Port Angeles120051990
Warm Beach120121998

Osprey Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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