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Species · Utah · BBS 2025 Release · 1966–2024

Warbling Vireo Population Trend in Utah

All statesForest birds

Warbling Vireo in Utah has surged: up 808% on the route-weighted index since 1972.

+808%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 →
64Routes 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 →
53YearsYears 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 808% 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 38% by 2029 — from 4.9 in 2024 to a central estimate of 6.8 (95% range 2.0–12). A 5-year backtest shows a typical error of ±70%, with 100% of held-out values landing inside the 95% band.

+38%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 →
6.8Projected 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 →
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 →
±70%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 38% by 2029 — from 4.9 in 2024 to a central estimate of 6.8 (95% range 2.0–12). A 5-year backtest shows a typical error of ±70%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20256.71.811
20266.71.912
20276.71.912
20286.81.912
20296.82.012

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 Rdge3720241986
Navajo Lake3020241970
Gooseberry3020241994
Logan Canyon2620191997
Fish Lake Nf2520241993
Main Canyon2520241992
La Sal 22420062003
Hardware Ranch2420231994
Moon Lake 22220232004
Beck 22220181990
La Sal 32220242007
Oak City2120241979
Beaver2120241968
Wasatch Nf1820241988
Alton 21720242021
Ferron1720222000
La Sal1520001993
Ant Flat-Ogden Can1420231994
Richfield1120191994
Heber Mtn.1020241996
Lost Cr. Res920181995
Soapstone920241992
Red Spur Mtn.720231997

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 2026-05-22.