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Species · Oregon · BBS 2026 Release · 1966–2025

Chestnut-backed Chickadee Population Trend in Oregon

All statesForest birds

Chestnut-backed Chickadee in Oregon has surged: up 137% on the route-weighted index since 1970.

+137%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 →
59Routes 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 OregonNotable 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 Oregon: up 137% on the route-weighted index since 1970.

Chestnut-backed Chickadee Population Forecast in Oregon

If the recent trend holds, Chestnut-backed Chickadee in Oregon is projected to fall about 12% by 2030 — from 4.6 in 2025 to a central estimate of 4.1 (95% range 2.6–5.6). A 5-year backtest shows a typical error of ±28%, with 100% of held-out values landing inside the 95% band.

-12%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 →
4.1Projected 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 →
2.6–5.695% 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 →
±28%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 Oregon is projected to fall about 12% by 2030 — from 4.6 in 2025 to a central estimate of 4.1 (95% range 2.6–5.6). A 5-year backtest shows a typical error of ±28%, with 100% 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 →
20263.92.35.4
20273.92.45.4
20284.02.55.5
20294.02.55.5
20304.12.65.6

Chestnut-backed Chickadee Survey Routes in Oregon

Routes recording Chestnut-backed Chickadee in Oregon.
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 →
Elkton6120251972
Fisher4720101997
Clearwater3820251991
Wedderburn3520251970
Hazel Camp3320221975
Ruch3320251992
Cinderella2720251993
Bull Run2520252007
Harlan 22320252012
Shellrock1920241968
Nicolai Mtn.1920251993
Coquille1820251994
Fisher 21720252017
Santiam1620251994
Lobster Creek1620252025
Waldport1620011992
Lorane1620251993
Winberry1420231968
Green1420251994
Klickitat Mt1419961993
Garfield1320251975
Blue River1320251992
Mt Hood1020251972
Harlan1020092006
Sandy River920061993

Chestnut-backed Chickadee Population Trend in Other States

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