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

Blackpoll Warbler In BCR 4

All regionsBCR 4Forest birds

Blackpoll Warbler in BCR 4 has increased: up 48% on the route-weighted index since 1976.

+48%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 →
60Routes 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 →
48YearsYears 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 →

No notable trend signals for Blackpoll Warbler in BCR 4. See the full index history below.

Blackpoll Warbler In BCR 4 Population Forecast

If the recent trend holds, Blackpoll Warbler in BCR 4 is projected to rise about 102% by 2030 — from 2.5 in 2025 to a central estimate of 5.0 (95% range 0.58–9.3). A 5-year backtest shows a typical error of ±121.3%, with 100% of held-out values landing inside the 95% band.

+102%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 →
5.0Projected 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 →
0.58–9.395% 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 →
±121.3%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, Blackpoll Warbler in BCR 4 is projected to rise about 102% by 2030 — from 2.5 in 2025 to a central estimate of 5.0 (95% range 0.58–9.3). A 5-year backtest shows a typical error of ±121.3%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20265.00.589.3
20275.00.589.3
20285.00.589.3
20295.00.589.3
20305.00.589.3

Routes In BCR 4

Routes recording Blackpoll Warbler 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 →
Goose BayALASKA331982
Mud RiverALASKA282024
Skilak LakeALASKA211985
MonahanALASKA182021
WasillaALASKA181983
Hather CreekALASKA172024
CantwellALASKA142025
PetersvilleALASKA142025
HomerALASKA121982
SavageALASKA122025
MaclarenALASKA92025
RubyALASKA92025
CircleALASKA72018
MatanuskaALASKA71983
Caribou Mtn.ALASKA72021
Galena (Short)ALASKA62025
Lake LouiseALASKA52025
Burma RoadALASKA52025
Unalakleet RiverALASKA52024
Mt. FairplayALASKA52016
Anvik RiverALASKA52024
TatalinaALASKA52019
Kobuk River (Short)ALASKA51992
WillowALASKA42025
Swan Lake RdALASKA42017

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