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Species · Washington · BBS 2025 Release · 1966–2024

Chestnut-backed Chickadee Population Trend in Washington

All statesForest birds

Chestnut-backed Chickadee in Washington has risen sharply: up 65% on the route-weighted index since 1970.

+65%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 →
60Routes 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 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 risen sharply in Washington: up 65% 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 28% by 2029 — from 8.9 in 2024 to a central estimate of 6.4 (95% range 3.7–9.1). A 5-year backtest shows a typical error of ±21.5%, with 60% of held-out values landing inside the 95% band.

-28%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 →
6.4Projected 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 →
3.7–9.195% 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 →
±21.5%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 28% by 2029 — from 8.9 in 2024 to a central estimate of 6.4 (95% range 3.7–9.1). A 5-year backtest shows a typical error of ±21.5%, 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 →
20256.23.58.9
20266.33.69.0
20276.33.69.0
20286.33.79.0
20296.43.79.1

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.5820241995
Cougar4820231968
Glacier4420241975
Port Angeles3620241970
Neilton3619751975
Index 23420232014
Mt. Adams3220241994
Warm Beach2420171968
Raymond 22320242022
Ozette2220241971
Sullivan Lake 22220242014
Kendall2120241981
Rainier2120191993
Carnation2120241988
Issaquah2019871969
Kamilche1820241969
E. Mt. Adams1820241995
Hurricane Rg1820241992
Mt St Helens1720241992
Ilwaco1620241975
South Elma1420241975
Mt Rainier1420211991
Cedar Falls1220141993
Warm Beach 21220242018
Snowden1120241987

Chestnut-backed Chickadee Population Trend in Other States

alaskacaliforniaidahomontanaoregon

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