BirdAnalyst
Species · Washington · BBS 2026 Release · 1966–2025

Bewick's Wren Population Trend in Washington

All statesForest birds

Bewick's Wren in Washington has risen sharply: up 60% on the route-weighted index since 1970.

+60%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 →
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 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 →

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 →

Bewick's Wren has risen sharply in Washington: up 60% on the route-weighted index since 1970.

Bewick's Wren Population Forecast in Washington

If the recent trend holds, Bewick's Wren in Washington is projected to fall about 50% by 2030 — from 1.8 in 2025 to a central estimate of 0.87 (95% range 0.10–1.6). A 5-year backtest shows a typical error of ±40.8%, with 60% of held-out values landing inside the 95% band.

-50%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 →
0.87Projected 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 →
0.10–1.695% 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 →
±40.8%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 50% by 2030 — from 1.8 in 2025 to a central estimate of 0.87 (95% range 0.10–1.6). A 5-year backtest shows a typical error of ±40.8%, with 60% 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 →
20260.890.111.7
20270.880.111.7
20280.880.101.7
20290.880.101.6
20300.870.101.6

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 →
Mukilteo1420251993
Mcchord1220151996
Mendota 31120252005
Everett1020251975
Port Angeles920251971
Mendota 2920001989
Ilwaco920251975
Vashon Is.820251995
South Elma720241975
Rainier620251993
Warm Beach520171968
Ewan 2520252023
Issaquah419871969
Wapato420221976
Raymond420211993
Bay View420161994
Yakima420251994
Warm Beach 2420242018
Prescott320041987
Pe Ell320251993
Newhalem219721969
Kamilche220251968
Bunker Hill220221968
Cougar219931970
Snowden220181997

Bewick's Wren Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoidahoillinoisindianaiowakansaskentuckymarylandmississippimissourinevadanew-mexiconorth-carolinaohiooklahomaoregonpennsylvaniatennesseetexasutahvirginiawest-virginiawisconsinwyoming

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