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Species · Washington · BBS 2026 Release · 1966–2025

Chestnut-backed Chickadee Population Trend in Washington

All statesForest birds

Chestnut-backed Chickadee in Washington has surged: up 93% on the route-weighted index since 1970.

+93%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 Chestnut-backed Chickadee 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 →

Chestnut-backed Chickadee has surged in Washington: up 93% on the route-weighted index since 1970.

Chestnut-backed Chickadee Population Forecast in Washington

If the recent trend holds, Chestnut-backed Chickadee in Washington is projected to fall about 32% by 2030 — from 9.9 in 2025 to a central estimate of 6.7 (95% range 3.9–9.5). A 5-year backtest shows a typical error of ±24.8%, with 40% of held-out values landing inside the 95% band.

-32%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 →
6.7Projected 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 →
3.9–9.595% 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 →
±24.8%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, Chestnut-backed Chickadee in Washington is projected to fall about 32% by 2030 — from 9.9 in 2025 to a central estimate of 6.7 (95% range 3.9–9.5). A 5-year backtest shows a typical error of ±24.8%, with 40% 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 →
20266.53.79.3
20276.63.89.4
20286.63.89.4
20296.73.89.5
20306.73.99.5

Chestnut-backed Chickadee Survey Routes in Washington

Routes recording Chestnut-backed Chickadee 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.5620251995
Cougar4820231968
Glacier4420241975
Rainier4420251993
Port Angeles3920251970
Neilton3619751975
Index 23420232014
Mt. Adams3420251994
E. Mt. Adams2720251995
Warm Beach2420171968
Ilwaco2420251975
Raymond 22320242022
Carnation2220251988
Issaquah2019871969
Everett1920251975
Hurricane Rg1920251992
Pe Ell1920251993
Kendall1820251981
L. Wenatchee1520251994
Ozette1420251971
Snowden1420251987
South Elma1420241975
Mt Rainier1420211991
Kamilche1320251969
Cusick1220251984

Chestnut-backed Chickadee Population Trend in Other States

alaskacaliforniaidahomontanaoregon

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