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Species · Alaska · BBS 2025 Release · 1966–2024

Warbling Vireo Population Trend in Alaska

All statesForest birds

Warbling Vireo in Alaska has surged: up 778% on the route-weighted index since 1993.

+778%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 →
33YearsYears 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 778% 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 fall about 25% by 2029 — from 0.72 in 2024 to a central estimate of 0.54 (95% range 0.07–1.0). A 5-year backtest shows a typical error of ±30.6%, with 80% of held-out values landing inside the 95% band.

-25%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 →
0.54Projected 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 →
0.07–1.095% 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 →
±30.6%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, Warbling Vireo in Alaska is projected to fall about 25% by 2029 — from 0.72 in 2024 to a central estimate of 0.54 (95% range 0.07–1.0). A 5-year backtest shows a typical error of ±30.6%, with 80% of held-out values landing inside the 95% band.19902029
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 →
20250.510.040.98
20260.520.040.99
20270.520.051.00
20280.530.061.0
20290.540.071.0

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 →
Haines1820241991
Stikine River1620241998
Ketchikan1020221998
Skagway520241993
Mitkof Isle520241994
Zimovia Strt220242016
Zarembo220242016
Juneau120021994
Hyder120091995
Thorne Bay119901990
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 2026-05-22.