BirdAnalyst
Species · BCR 2 · BBS 2025 Release · 1966–2024

Blackpoll Warbler In BCR 2

All regionsBCR 2Forest birds

Blackpoll Warbler in BCR 2 has collapsed: down 76% on the route-weighted index since 1987.

-76%Since 1987TrendPercent 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 →
16Routes 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 →
34YearsYears 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 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 →

Blackpoll Warbler has collapsed in BCR 2: down 76% on the route-weighted index since 1987.

Forecast

If the recent trend holds, Blackpoll Warbler in BCR 2 is projected to fall about 16% by 2029 — from 2.7 in 2024 to a central estimate of 2.2 (95% range 0.00–7.7). A 5-year backtest shows a typical error of ±122.6%, with 100% of held-out values landing inside the 95% band.

-16%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 →
2.2Projected 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 →
0.00–7.795% 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 →
±122.6%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 2 is projected to fall about 16% by 2029 — from 2.7 in 2024 to a central estimate of 2.2 (95% range 0.00–7.7). A 5-year backtest shows a typical error of ±122.6%, with 100% of held-out values landing inside the 95% band.19842029
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 →
20252.90.008.4
20262.80.008.3
20272.60.008.1
20282.40.007.9
20292.20.007.7

Routes In BCR 2

Routes recording Blackpoll Warbler in BCR 2.
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 →
TupuknukALASKA741995
Gweek RiverALASKA442002
DillinghamALASKA412019
Togiak RiverALASKA232005
Dillingham (Short)ALASKA221984
Selawik (Short)ALASKA221987
King SalmonALASKA202024
Kugarak (Short)ALASKA141987
Goodnews BayALASKA102005
St. Mary'SALASKA62014
Kanektok RivALASKA62005
Katmai N.P.ALASKA52022
CouncilALASKA42024
NomeALASKA32012
KotzebueALASKA22016
Salmon LakeALASKA12019

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