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Species · Utah · BBS 2026 Release · 1966–2025

Virginia's Warbler Population Trend in Utah

All statesForest birds

Virginia's Warbler in Utah has fallen sharply: down 71% on the route-weighted index since 1988.

-71%Since 1988TrendPercent 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 →
39YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Virginia's Warbler 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 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 →

Virginia's Warbler has fallen sharply in Utah: down 71% on the route-weighted index since 1988.

Virginia's Warbler Population Forecast in Utah

If the recent trend holds, Virginia's Warbler in Utah is projected to fall about 100% by 2030 — from 0.73 in 2025 to a central estimate of 0.00 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±109.1%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1.495% 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 →
±109.1%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, Virginia's Warbler in Utah is projected to fall about 100% by 2030 — from 0.73 in 2025 to a central estimate of 0.00 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±109.1%, 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 →
20260.080.001.5
20270.060.001.4
20280.040.001.4
20290.010.001.4
20300.000.001.4

Virginia's Warbler Survey Routes in Utah

Routes recording Virginia's Warbler 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 →
Fayette1420251994
Beaver620251992
Newcastle520251997
La Sal 3520252007
Saleratus Cr420001995
Fish Lake Nf420252018
Altonah320251968
La Sal 2320062003
Bryce Canyon320241996
Crawford Mts320232023
Skyline Driv320152012
Gooseberry320251996
Alton320111997
Lost Cr. Res220151995
Book Ridge220252003
Hite220071993
Shivwitz220111994
Beck 2220251990
Ferron220252004
Ant Flat-Ogden Can220221994
Uintah Nf219941994
Moquith Mtn220021987
Moon Lake 2120232013
Grizzly Rdge120222022
Oak City120231987

Virginia's Warbler Population Trend in Other States

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