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Species · New Hampshire · BBS 2025 Release · 1966–2024

Boreal Chickadee Population Trend in New Hampshire

All statesForest birds

Boreal Chickadee in New Hampshire has collapsed: down 81% on the route-weighted index since 1968.

-81%Since 1968TrendPercent 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 →
6Routes 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 →
27YearsYears 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 New HampshireNotable 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 New Hampshire: down 81% on the route-weighted index since 1968.

Boreal Chickadee Population Forecast in New Hampshire

If the recent trend holds, Boreal Chickadee in New Hampshire is projected to stay roughly flat through 2027, near 0.06 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±47.3%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.06Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2795% 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 →
±47.3%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, Boreal Chickadee in New Hampshire is projected to stay roughly flat through 2027, near 0.06 (95% range 0.00–0.27). A 5-year backtest shows a typical error of ±47.3%, with 100% of held-out values landing inside the 95% band.19662027
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 →
20230.070.000.27
20240.070.000.27
20250.070.000.27
20260.060.000.27
20270.060.000.27

Boreal Chickadee Survey Routes in New Hampshire

Routes recording Boreal Chickadee in New Hampshire.
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 →
Crawford Not219721972
Milan119961967
Stratford120042004
Dixvil Notch120031966
Clarksville120131969
Jeffers Ntch120222007

Boreal Chickadee Population Trend in Other States

alaskamainemichiganminnesotamontananew-yorkvermontwisconsin

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