BirdAnalyst
Species · Alaska · BBS 2026 Release · 1966–2025

Warbling Vireo Population Trend in Alaska

All statesForest birds

Warbling Vireo in Alaska has surged: up 551% on the route-weighted index since 1993.

+551%Since 1993TrendPercent 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 →
11Routes 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 →
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 Warbling Vireo 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 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 →

Warbling Vireo has surged in Alaska: up 551% on the route-weighted index since 1993.

Warbling Vireo Population Forecast in Alaska

If the recent trend holds, Warbling Vireo in Alaska is projected to rise about 32% by 2030 — from 0.40 in 2025 to a central estimate of 0.53 (95% range 0.06–0.99). A 5-year backtest shows a typical error of ±27.3%, with 80% of held-out values landing inside the 95% band.

+32%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 →
0.53Projected 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 →
0.06–0.9995% 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 →
±27.3%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, Warbling Vireo in Alaska is projected to rise about 32% by 2030 — from 0.40 in 2025 to a central estimate of 0.53 (95% range 0.06–0.99). A 5-year backtest shows a typical error of ±27.3%, with 80% 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 →
20260.500.040.96
20270.510.040.97
20280.510.050.98
20290.520.060.98
20300.530.060.99

Warbling Vireo Survey Routes in Alaska

Routes recording Warbling Vireo 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 →
Haines1720251991
Stikine River1620241998
Ketchikan1020221998
Skagway420251993
Zarembo220242016
Zimovia Strt120252016
Juneau120021994
Hyder120091995
Thorne Bay119901990
Mitkof Isle120251994
Thorne Bay 2120172016

Warbling Vireo Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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