BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Chestnut-backed Chickadee In Northern Rockies

All regionsNorthern RockiesForest birds

Chestnut-backed Chickadee in Northern Rockies has surged: up 393% on the route-weighted index since 1979.

+393%Since 1979TrendPercent 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 →
35Routes 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 →
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 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 →

Chestnut-backed Chickadee has surged in Northern Rockies: up 393% on the route-weighted index since 1979.

Forecast

If the recent trend holds, Chestnut-backed Chickadee in Northern Rockies is projected to rise about 47% by 2029 — from 0.51 in 2024 to a central estimate of 0.75 (95% range 0.51–0.99). A 5-year backtest shows a typical error of ±40.1%, with 40% of held-out values landing inside the 95% band.

+47%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 →
0.75Projected 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 →
0.51–0.9995% 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 →
±40.1%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 Northern Rockies is projected to rise about 47% by 2029 — from 0.51 in 2024 to a central estimate of 0.75 (95% range 0.51–0.99). A 5-year backtest shows a typical error of ±40.1%, with 40% of held-out values landing inside the 95% band.19772029
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 →
20250.700.460.94
20260.710.480.95
20270.730.490.97
20280.740.500.98
20290.750.510.99

Routes In Northern Rockies

Routes recording Chestnut-backed Chickadee in Northern Rockies.
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 →
Sullivan Lake 2WASHINGTON222024
N Fork Cda RIDAHO122019
CoolinIDAHO112024
CusickWASHINGTON112024
PierceIDAHO102007
NaplesIDAHO62024
MivodenIDAHO62023
Baldy MountainIDAHO62014
Marble CreekIDAHO62023
Rochat DivdeIDAHO62023
GrangevilleIDAHO42024
L Pend O NwrWASHINGTON42024
Lolo PassIDAHO32019
St RegisMONTANA32024
NoxonMONTANA32023
Logan PassMONTANA32023
NezperceIDAHO22008
Fish CreekMONTANA22022
Twin LakesWASHINGTON22024
NorthportWASHINGTON22024
AveryIDAHO12023
GoldenIDAHO12013
Nezperce NfIDAHO11998
Salmon RiverIDAHO12009
Libby DamMONTANA12024

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