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

Bewick's Wren Population Trend in Washington

All statesForest birds

Bewick's Wren in Washington has increased: up 35% on the route-weighted index since 1970.

+35%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 →
61Routes 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 Bewick's Wren 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 →

No notable trend signals for Bewick's Wren in Washington. See the full index history below.

Bewick's Wren Population Forecast in Washington

If the recent trend holds, Bewick's Wren in Washington is projected to fall about 52% by 2029 — from 1.7 in 2024 to a central estimate of 0.81 (95% range 0.06–1.6). A 5-year backtest shows a typical error of ±36%, with 80% of held-out values landing inside the 95% band.

-52%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 →
0.81Projected 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 →
0.06–1.695% 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 →
±36%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, Bewick's Wren in Washington is projected to fall about 52% by 2029 — from 1.7 in 2024 to a central estimate of 0.81 (95% range 0.06–1.6). A 5-year backtest shows a typical error of ±36%, with 80% 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 →
20250.830.081.6
20260.820.071.6
20270.820.071.6
20280.810.061.6
20290.810.061.6

Bewick's Wren Survey Routes in Washington

Routes recording Bewick's Wren 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 →
Mukilteo2220241993
Mendota 31520242005
Mcchord1220151996
Everett1220241975
Vashon Is.1020241995
Mendota 2920001989
South Elma720241975
Warm Beach520171968
Yakima520241994
Issaquah419871969
Wapato420221976
Raymond420211993
Bay View420161994
Rainier420181993
Warm Beach 2420242018
Ewan 2320242023
Ilwaco320241975
Prescott320041987
Carnation320241988
Newhalem219721969
Kamilche220241968
Bunker Hill220221968
Cougar219931970
Snowden220181997
Raymond 2220242022

Bewick's Wren Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoidahoillinoisindianaiowakansaskentuckymarylandmississippimissourinevadanew-mexiconorth-carolinaohiooklahomaoregonpennsylvaniatennesseetexasutahvirginiawest-virginiawisconsinwyoming

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