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

Brown Creeper Population Trend in Washington

All statesForest birds

Brown Creeper in Washington has surged: up 402% on the route-weighted index since 1971.

+402%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 →
55YearsYears 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 402% 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 14% by 2029 — from 1.5 in 2024 to a central estimate of 1.3 (95% range 0.95–1.7). A 5-year backtest shows a typical error of ±18.7%, with 60% of held-out values landing inside the 95% band.

-14%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 →
1.3Projected 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 →
0.95–1.795% 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 →
±18.7%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 14% by 2029 — from 1.5 in 2024 to a central estimate of 1.3 (95% range 0.95–1.7). A 5-year backtest shows a typical error of ±18.7%, with 60% 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 →
20251.20.861.6
20261.20.881.6
20271.30.911.6
20281.30.931.7
20291.30.951.7

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.1220241997
Deception820181995
Glacier820241979
Carnation820241989
Cougar620231985
E. Mt. Adams620241996
Kendall620241981
Rainier620191993
Bunker Hill520241969
Raymond 2520242022
Neilton419751975
Omak Creek420242007
Deer Park420082001
Greenwater420242016
Ronald320241973
Cedar Falls320141996
Mt St Helens320242002
Mt Rainier320151993
Mendota 3320242005
Port Angeles220231974
Warm Beach220161969
Montesand220242004
Issaquah219871969
Rimrock220231969
Mcchord220151996

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 2026-05-22.