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Species · Washington · BBS 2025 Release · 1966–2024

Swainson's Hawk Population Trend in Washington

All statesGeneralists

Swainson's Hawk in Washington has surged: up 208% on the route-weighted index since 1971.

+208%Since 1971
40Routes In State
55Years

Notable Swainson's Hawk Trends in Washington

long arc increasecomputed index

Swainson's Hawk has surged in Washington: up 207% on the route-weighted index since 1971.

Swainson's Hawk Population Forecast in Washington

If the recent trend holds, Swainson's Hawk in Washington is projected to rise about 36% by 2029 — from 0.37 in 2024 to a central estimate of 0.50 (95% range 0.30–0.70). A 5-year backtest shows a typical error of ±96.1%, with 60% of held-out values landing inside the 95% band.

+36%Change by 2029
0.50Projected 2029 index
0.30–0.7095% range
±96.1%Backtest error
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 index95% low95% high
20250.470.280.67
20260.480.280.68
20270.490.290.69
20280.490.300.69
20290.500.300.70

Swainson's Hawk Survey Routes in Washington

Routes recording Swainson's Hawk in Washington.
Keystone820241994
Columbia Nwr620221996
Sulphur520221995
Hatton519941992
Richland420242006
Moses Lake320221974
Snowden319841982
Hartline320221995
Horn Rapids320242005
Selah220162002
Ewan 2220232023
Harrington220121973
Connell220151968
Bickleton220041982
Ewan220091989
Scootney Reservoir220242009
Potholes220191996
Moses Coulee220211993
Odessa220241993
Yakima220022002
Hanford Site119961988
Arid Land Er119961988
Brewster119851977
Wapato119721972
Mercer120211969

Swainson's Hawk Population Trend in Other States

arizonaarkansascaliforniacoloradoidahoillinoisiowakansaslouisianaminnesotamissourimontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwisconsinwyoming

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