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Species · Maine · BBS 2025 Release · 1966–2024

Boreal Chickadee Population Trend in Maine

All statesForest birds

Boreal Chickadee in Maine has collapsed: down 90% on the route-weighted index since 1976.

-90%Since 1976TrendPercent 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 →
36Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Boreal Chickadee Trends in MaineNotable 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 declinecomputed 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 →

Boreal Chickadee has collapsed in Maine: down 90% on the route-weighted index since 1976.

Boreal Chickadee Population Forecast in Maine

If the recent trend holds, Boreal Chickadee in Maine is projected to fall about 33% by 2026 — from 0.08 in 2021 to a central estimate of 0.05 (95% range 0.00–0.77). A 5-year backtest shows a typical error of ±125.7%, with 100% of held-out values landing inside the 95% band.

-33%Change by 2026TrendPercent 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 →
0.05Projected 2026 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.7795% 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 →
±125.7%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 →
19682026
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 →
20220.080.000.80
20230.080.000.79
20240.070.000.78
20250.060.000.78
20260.050.000.77

Boreal Chickadee Survey Routes in Maine

Routes recording Boreal Chickadee in Maine.
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 →
Pillsbury Pd1419681968
Waite519771977
Wytopitlock419791978
Clayton Lake420011977
Big Twenty 2320092009
Baker Lake 2320102010
Big Twenty320071995
Yankeetuladi320091995
Northfield 2220212021
Heron Lake220031989
Cooper219971976
Seboomook Lk220101990
Cambridge219721972
Grnd Lk Strm219901990
Ludlow219931968
Lake Moxie220092009
Weeks Brook220151995
Wilson Mills120191983
Bethel120081978
Nesowadnehun120191998
Topsfield119961996
Clayton Lake 2120102010
Eastbrook119861986
Northfield119811981
Moose River120061986

Boreal Chickadee Population Trend in Other States

alaskamichiganminnesotamontananew-hampshirenew-yorkvermontwisconsin

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