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Species · BCR 4 · BBS 2025 Release · 1966–2024

Boreal Chickadee In BCR 4

All regionsBCR 4Forest birds

Boreal Chickadee in BCR 4 has surged: up 137% on the route-weighted index since 1978.

+137%Since 1978TrendPercent 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 →
61Routes In RegionSurvey 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 SignalsNotable 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 →

Boreal Chickadee has surged in BCR 4: up 137% on the route-weighted index since 1978.

Boreal Chickadee In BCR 4 Population Forecast

If the recent trend holds, Boreal Chickadee in BCR 4 is projected to rise about 36% by 2029 — from 1.5 in 2024 to a central estimate of 2.1 (95% range 1.1–3.1). A 5-year backtest shows a typical error of ±18.7%, with 100% of held-out values landing inside the 95% band.

+36%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 →
2.1Projected 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 →
1.1–3.195% 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 →
±18.7%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 →
If the recent trend holds, Boreal Chickadee in BCR 4 is projected to rise about 36% by 2029 — from 1.5 in 2024 to a central estimate of 2.1 (95% range 1.1–3.1). A 5-year backtest shows a typical error of ±18.7%, with 100% of held-out values landing inside the 95% band.19752029
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 →
20252.01.03.0
20262.01.03.0
20272.01.13.0
20282.11.13.0
20292.11.13.1

Routes In BCR 4

Routes recording Boreal Chickadee in BCR 4.
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 →
SlanaALASKA92024
KuskulanaALASKA92024
Kanuti LakeALASKA82024
Birch LakeALASKA72021
ChistochinaALASKA62024
ChickenALASKA62023
DeltaALASKA62024
TatalinaALASKA62019
Swan Lake RdALASKA52023
HomerALASKA41982
Chena RiverALASKA41988
Nicholai SlALASKA42019
Tower BluffsALASKA32023
NorthwayALASKA32023
Skilak LakeALASKA31985
WillowALASKA32022
SavageALASKA32024
Anchor RiverALASKA32024
Moose CreekALASKA32022
Murphy DomeALASKA32023
Ft. RichrdsnALASKA32022
Mccarthy Rd2ALASKA32024
Chatanika RALASKA22023
LivengoodALASKA22021
NebesnaALASKA21975

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