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Species · Alaska · BBS 2026 Release · 1966–2025

Arctic Warbler Population Trend in Alaska

All statesForest birds

Arctic Warbler in Alaska has fallen sharply: down 50% on the route-weighted index since 1984.

-50%Since 1984TrendPercent 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 →
42Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
41YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Arctic Warbler Trends in AlaskaNotable 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 →

Arctic Warbler has fallen sharply in Alaska: down 50% on the route-weighted index since 1984.

Arctic Warbler Population Forecast in Alaska

If the recent trend holds, Arctic Warbler in Alaska is projected to rise about 23% by 2030 — from 1.9 in 2025 to a central estimate of 2.3 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±25.8%, 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 →
2.3Projected 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 →
0.00–5.395% 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 →
±25.8%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, Arctic Warbler in Alaska is projected to rise about 23% by 2030 — from 1.9 in 2025 to a central estimate of 2.3 (95% range 0.00–5.3). A 5-year backtest shows a typical error of ±25.8%, with 100% of held-out values landing inside the 95% band.19822030
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 →
20262.50.005.5
20272.50.005.5
20282.40.005.4
20292.40.005.4
20302.30.005.3

Arctic Warbler Survey Routes in Alaska

Routes recording Arctic Warbler in Alaska.
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 →
Maclaren7320251982
Goodnews Bay5520051999
Salmon Lake5220241993
Togiak River4220051999
Paxson Lake4019971991
Nome3620231993
Copper River2419971997
Dillingham (Short)2419841984
Council1420241993
Toklat1220241982
Red Dog1220252023
Dillingham1120191996
Kanektok Riv1120051995
Cantwell820251982
Savage820251987
Mcgrath720221997
Tatalina620191996
Dietrich Cmp620141993
St. Mary'S520141993
Coldfoot420221999
Teller420241993
Sheep Mtn420251983
Cape Nome320171998
Chena Hot Sp319871986
Gweek River320012000

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