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Species · Alaska · BBS 2025 Release · 1966–2024

Chestnut-backed Chickadee Population Trend in Alaska

All statesForest birds

Chestnut-backed Chickadee in Alaska has surged: up 169% on the route-weighted index since 1975.

+169%Since 1975TrendPercent 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 →
28Routes 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 →
45YearsYears 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 AlaskaNotable 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 Alaska: up 169% on the route-weighted index since 1975.

Chestnut-backed Chickadee Population Forecast in Alaska

If the recent trend holds, Chestnut-backed Chickadee in Alaska is projected to fall about 18% by 2029 — from 3.3 in 2024 to a central estimate of 2.7 (95% range 0.04–5.4). A 5-year backtest shows a typical error of ±19.6%, with 100% of held-out values landing inside the 95% band.

-18%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 →
2.7Projected 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 →
0.04–5.495% 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 →
±19.6%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, Chestnut-backed Chickadee in Alaska is projected to fall about 18% by 2029 — from 3.3 in 2024 to a central estimate of 2.7 (95% range 0.04–5.4). A 5-year backtest shows a typical error of ±19.6%, with 100% of held-out values landing inside the 95% band.19722029
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 →
20252.80.075.4
20262.70.065.4
20272.70.055.4
20282.70.045.4
20292.70.045.4

Chestnut-backed Chickadee Survey Routes in Alaska

Routes recording Chestnut-backed Chickadee in Alaska.
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 →
Whale Pass4420241997
Zarembo3620241993
Petersburg2719871987
Craig2620241983
Thorne Bay 22620242013
Beaver Creek2119771977
Haines1920241972
Sitka (Short)1919921984
Hyder1320091994
Kuiu Island1120102004
Yakutat (Short)1119841984
Mitkof Isle1120241988
Zimovia Strt1020241988
Yakutat920241993
Skagway820241993
Sitka820241993
Thorne Bay720121989
Stikine River620241998
Chichagof Is620241994
Ketchikan520221974
Juneau420241983
Hoonah420241993
Harlequin L.420241993
Wrangell (Short)319841984
Thompson Pas220222006

Chestnut-backed Chickadee Population Trend in Other States

californiaidahomontanaoregonwashington

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