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Species · Utah · BBS 2025 Release · 1966–2024

Lucy's Warbler Population Trend in Utah

All statesArid-land birds

Lucy's Warbler in Utah has surged: up 682% on the route-weighted index since 1994.

+682%Since 1994TrendPercent 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 →
6Routes 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 →
25YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Lucy'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 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 →

Lucy's Warbler has surged in Utah: up 682% on the route-weighted index since 1994.

Lucy's Warbler Population Forecast in Utah

If the recent trend holds, Lucy's Warbler in Utah is projected to rise about 80% by 2029 — from 0.12 in 2024 to a central estimate of 0.21 (95% range 0.09–0.34). A 5-year backtest shows a typical error of ±40.1%, with 40% of held-out values landing inside the 95% band.

+80%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 →
0.21Projected 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 →
0.09–0.3495% 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 →
±40.1%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, Lucy's Warbler in Utah is projected to rise about 80% by 2029 — from 0.12 in 2024 to a central estimate of 0.21 (95% range 0.09–0.34). A 5-year backtest shows a typical error of ±40.1%, with 40% of held-out values landing inside the 95% band.19922029
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 →
20250.190.070.31
20260.200.070.32
20270.200.080.33
20280.210.080.33
20290.210.090.34

Lucy's Warbler Survey Routes in Utah

Routes recording Lucy'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 →
Hatch220242016
Aneth220242024
Moquith Mtn220032002
Moab220242014
Shivwitz120241992
Newcastle120162007

Lucy's Warbler Population Trend in Other States

arizonacalifornianevadanew-mexicotexas

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