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

American Bittern Population Trend in Washington

All statesWetland birds

American Bittern in Washington has fallen sharply: down 64% on the route-weighted index since 1976.

-64%Since 1976
17Routes In State
44Years

Notable American Bittern Trends in Washington

long arc declinecomputed index

American Bittern has fallen sharply in Washington: down 64% on the route-weighted index since 1976.

American Bittern Population Forecast in Washington

If the recent trend holds, American Bittern in Washington is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.10). A 5-year backtest shows a typical error of ±31.4%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2029
0.02Projected 2029 index
0.00–0.1095% range
±31.4%Backtest error
19742029
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
20250.030.000.10
20260.030.000.10
20270.020.000.10
20280.020.000.10
20290.020.000.10

American Bittern Survey Routes in Washington

Routes recording American Bittern in Washington.
Mendota 2320001990
Turnbull Nwr320162000
Issaquah219861980
South Elma220051984
Moses Lake220041976
Potholes220192013
Everett119981998
Ilwaco119901975
Taholah119891989
Kamilche119881974
Mendota119881977
Mukilteo119981998
Carnation120181990
Columbia Nwr120212005
Mendota 3120242017
Keystone120181996
Raymond119941994

American Bittern Population Trend in Other States

alaskacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatexasutahvermontvirginiawest-virginiawisconsinwyoming

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