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Species · Utah · BBS 2025 Release · 1966–2024

Black-throated Gray Warbler Population Trend in Utah

All statesForest birds

Black-throated Gray Warbler in Utah has edged down: down 18% on the route-weighted index since 1977.

-18%Since 1977TrendPercent 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 →
60Routes 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 →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black-throated Gray 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 →

No notable trend signals for Black-throated Gray Warbler in Utah. See the full index history below.

Black-throated Gray Warbler Population Forecast in Utah

If the recent trend holds, Black-throated Gray Warbler in Utah is projected to stay roughly flat through 2029, near 0.59 (95% range 0.02–1.2). A 5-year backtest shows a typical error of ±25.2%, with 100% of held-out values landing inside the 95% band.

+8%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 →
0.59Projected 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 →
0.02–1.295% 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 →
±25.2%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, Black-throated Gray Warbler in Utah is projected to stay roughly flat through 2029, near 0.59 (95% range 0.02–1.2). A 5-year backtest shows a typical error of ±25.2%, 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 →
20250.590.021.2
20260.590.021.2
20270.590.021.2
20280.590.021.2
20290.590.021.2

Black-throated Gray Warbler Survey Routes in Utah

Routes recording Black-throated Gray 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 →
Shivwitz1820171992
Glen Canyon920241995
Newcastle720221997
Willow Creek620241997
Alton 2620242021
Oak City420142004
Arches Np420101991
Canyonlands420061991
Grouse Creek419821982
Hanna420241998
Vernon320232016
Moab320121992
Cane Spr Des319931992
Lost Cr. Res219951995
Altonah220151999
Castleton219851977
Navajo Lake220031968
Boulder220211974
Hite220151993
Moon Lake220022001
Gooseberry220061997
Vernal220182016
Bicknell220162016
Alton220171997
Ant Flat-Ogden Can219991994

Black-throated Gray Warbler Population Trend in Other States

arizonacaliforniacoloradoidahonevadanew-mexicooregonwashingtonwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.