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Species · Utah · BBS 2026 Release · 1966–2025

Warbling Vireo Population Trend in Utah

All statesForest birds

Warbling Vireo in Utah has surged: up 865% on the route-weighted index since 1972.

+865%Since 1972TrendPercent 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 →
65Routes 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 →
54YearsYears 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 UtahNotable 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 Utah: up 865% on the route-weighted index since 1972.

Warbling Vireo Population Forecast in Utah

If the recent trend holds, Warbling Vireo in Utah is projected to rise about 27% by 2030 — from 5.3 in 2025 to a central estimate of 6.7 (95% range 2.0–12). A 5-year backtest shows a typical error of ±61.1%, with 100% of held-out values landing inside the 95% band.

+27%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 →
6.7Projected 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 →
2.0–1295% 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 →
±61.1%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 Utah is projected to rise about 27% by 2030 — from 5.3 in 2025 to a central estimate of 6.7 (95% range 2.0–12). A 5-year backtest shows a typical error of ±61.1%, with 100% 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 →
20266.61.811
20276.61.911
20286.71.911
20296.71.911
20306.72.012

Warbling Vireo Survey Routes in Utah

Routes recording Warbling Vireo in Utah.
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 →
Uintah Nf4019941987
Beck3919871972
Grizzly Rdge3220251986
Fish Lake Nf3220251993
Skyline Driv3020251986
Ferron2720252000
Logan Canyon2620191997
Navajo Lake2620251970
La Sal 22420062003
Beck 22420251990
Hardware Ranch2420231994
Gooseberry2320251994
Moon Lake 22220232004
La Sal 32220252007
Oak City2120241979
Beaver1920251968
Woodruff1820252002
Wasatch Nf1820241988
Main Canyon1820251992
Heber Mtn.1620251996
La Sal1520001993
Monticello1520251999
Alton 21420252021
Richfield1120191994
Lost Cr. Res920181995

Warbling Vireo Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsinwyoming

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