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

Brown Creeper Population Trend in Washington

All statesForest birds

Brown Creeper in Washington has surged: up 604% on the route-weighted index since 1971.

+604%Since 1971TrendPercent 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 →
68Routes 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 Brown Creeper 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 →

Brown Creeper has surged in Washington: up 604% on the route-weighted index since 1971.

Brown Creeper Population Forecast in Washington

If the recent trend holds, Brown Creeper in Washington is projected to fall about 44% by 2030 — from 2.6 in 2025 to a central estimate of 1.4 (95% range 0.94–1.9). A 5-year backtest shows a typical error of ±24.6%, with 60% of held-out values landing inside the 95% band.

-44%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 →
1.4Projected 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 →
0.94–1.995% 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 →
±24.6%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, Brown Creeper in Washington is projected to fall about 44% by 2030 — from 2.6 in 2025 to a central estimate of 1.4 (95% range 0.94–1.9). A 5-year backtest shows a typical error of ±24.6%, 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 →
20261.30.851.8
20271.40.871.9
20281.40.901.9
20291.40.921.9
20301.40.941.9

Brown Creeper Survey Routes in Washington

Routes recording Brown Creeper 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 →
Vashon Is.2620251997
Kendall1920251981
Rainier1520251993
Deception820181995
Glacier820241979
Carnation720251989
Cougar620231985
E. Mt. Adams620251996
Ilwaco620251977
Port Angeles520251974
Bunker Hill520251969
Raymond 2520242022
Hurricane Rg520251992
Ozette420251983
Neilton419751975
Omak Creek420242007
Deer Park420082001
Rimrock320251969
Sullivan Lake 2320252000
Cedar Falls320141996
Mt Rainier320151993
Warm Beach220161969
Montesand220242004
Kamilche220251983
Issaquah219871969

Brown Creeper Population Trend in Other States

alaskaarizonacaliforniacoloradoconnecticutidahoillinoisindianaiowamainemarylandmassachusettsmichiganminnesotamontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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