BirdAnalyst
Species · BCR 4 · BBS 2026 Release · 1966–2025

Red-breasted Nuthatch In BCR 4

All regionsBCR 4Forest birds

Red-breasted Nuthatch in BCR 4 has surged: up 622% on the route-weighted index since 1994.

+622%Since 1994TrendPercent 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 →
24Routes 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 →
33YearsYears 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 →

Red-breasted Nuthatch has surged in BCR 4: up 622% on the route-weighted index since 1994.

Red-breasted Nuthatch In BCR 4 Population Forecast

If the recent trend holds, Red-breasted Nuthatch in BCR 4 is projected to fall about 23% by 2030 — from 0.73 in 2025 to a central estimate of 0.56 (95% range 0.22–0.90). A 5-year backtest shows a typical error of ±33.4%, with 100% of held-out values landing inside the 95% band.

-23%Change by 2030TrendPercent 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 →
0.56Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.22–0.9095% 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 →
±33.4%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, Red-breasted Nuthatch in BCR 4 is projected to fall about 23% by 2030 — from 0.73 in 2025 to a central estimate of 0.56 (95% range 0.22–0.90). A 5-year backtest shows a typical error of ±33.4%, with 100% of held-out values landing inside the 95% band.19902030
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 →
20260.520.180.86
20270.530.190.87
20280.540.200.88
20290.550.210.89
20300.560.220.90

Routes In BCR 4

Routes recording Red-breasted Nuthatch 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 →
KachemakALASKA82025
WillowALASKA72025
KalifonskyALASKA62025
Anchor RiverALASKA42024
CohoeALASKA32023
Burma RoadALASKA22023
SlanaALASKA11997
ChistochinaALASKA12021
NorthwayALASKA12023
Kenny LakeALASKA12025
SourdoughALASKA11995
TonsinaALASKA12021
Hatcher PassALASKA12025
Swan Lake RdALASKA12023
Lake LouiseALASKA12025
Nicholai SlALASKA12025
PetersvilleALASKA12025
Seven LakesALASKA12024
Unalakleet RiverALASKA12010
Ft. RichrdsnALASKA12023
Galena (Short)ALASKA12024
Nabesna RoadALASKA11996
KuskulanaALASKA12025
Mccarthy Rd2ALASKA12024

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.