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

Orange-crowned Warbler In BCR 4

All regionsBCR 4Forest birds

Orange-crowned Warbler in BCR 4 has risen sharply: up 54% on the route-weighted index since 1978.

+54%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 →
68Routes 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 →
46YearsYears 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 →

Orange-crowned Warbler has risen sharply in BCR 4: up 54% on the route-weighted index since 1978.

Orange-crowned Warbler In BCR 4 Population Forecast

If the recent trend holds, Orange-crowned Warbler in BCR 4 is projected to rise about 63% by 2030 — from 12 in 2025 to a central estimate of 20 (95% range 13–28). A 5-year backtest shows a typical error of ±57.6%, with 0% of held-out values landing inside the 95% band.

+63%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 →
20Projected 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 →
13–2895% 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 →
±57.6%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, Orange-crowned Warbler in BCR 4 is projected to rise about 63% by 2030 — from 12 in 2025 to a central estimate of 20 (95% range 13–28). A 5-year backtest shows a typical error of ±57.6%, with 0% 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 →
2026201227
2027201327
2028201328
2029201328
2030201328

Routes In BCR 4

Routes recording Orange-crowned 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 →
Kanuti CanynALASKA572024
HomerALASKA521982
SavageALASKA522025
ToklatALASKA512024
Unalakleet RiverALASKA372022
KachemakALASKA352025
CohoeALASKA342023
Burma RoadALASKA312025
CottonwoodALASKA281990
KalifonskyALASKA272025
Anchor RiverALASKA272025
Moose CreekALASKA272022
Galena (Short)ALASKA262025
Hatcher PassALASKA232025
Chena RiverALASKA211988
EagleALASKA202025
Mt. FairplayALASKA192025
DeltaALASKA192024
MatanuskaALASKA181983
TatalinaALASKA172019
CircleALASKA162025
ChickenALASKA162025
Nicholai SlALASKA162025
Goose BayALASKA151982
Kanuti LakeALASKA152024

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