BirdAnalyst
Species · Utah · BBS 2025 Release · 1966–2024

Grace's Warbler Population Trend in Utah

All statesForest birds

Grace's Warbler in Utah has increased: up 40% on the route-weighted index since 1990.

+40%Since 1990TrendPercent 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 →
10Routes 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 Grace'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 →

No notable trend signals for Grace's Warbler in Utah. See the full index history below.

Grace's Warbler Population Forecast in Utah

If the recent trend holds, Grace's Warbler in Utah is projected to stay roughly flat through 2029, near 0.16 (95% range 0.00–0.36). A 5-year backtest shows a typical error of ±26.5%, with 100% of held-out values landing inside the 95% band.

-5%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 →
0.16Projected 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 →
0.00–0.3695% 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 →
±26.5%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, Grace's Warbler in Utah is projected to stay roughly flat through 2029, near 0.16 (95% range 0.00–0.36). A 5-year backtest shows a typical error of ±26.5%, with 100% of held-out values landing inside the 95% band.19872029
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 →
20250.160.000.36
20260.160.000.36
20270.160.000.36
20280.160.000.36
20290.160.000.36

Grace's Warbler Survey Routes in Utah

Routes recording Grace'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 →
Bryce Canyon520241990
Dixie Nf320241998
Navajo Lake320221987
La Sal219991999
Alton120191997
La Sal 2120042004
La Sal 3120242014
Ferron120212013
Moquith Mtn119991999
Main Canyon120242005

Grace's Warbler Population Trend in Other States

arizonacoloradonew-mexico

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