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

Wilson's Warbler Population Trend in Utah

All statesForest birds

Wilson's Warbler in Utah has collapsed: down 81% on the route-weighted index since 1977.

-81%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 →
29Routes 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 →
35YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Wilson'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 →

Wilson's Warbler has collapsed in Utah: down 81% on the route-weighted index since 1977.

Wilson's Warbler Population Forecast in Utah

If the recent trend holds, Wilson's Warbler in Utah is projected to fall about 100% by 2029 — from 0.07 in 2024 to a central estimate of 0.00 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±168.9%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.2395% 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 →
±168.9%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, Wilson's Warbler in Utah is projected to fall about 100% by 2029 — from 0.07 in 2024 to a central estimate of 0.00 (95% range 0.00–0.23). A 5-year backtest shows a typical error of ±168.9%, with 100% of held-out values landing inside the 95% band.19742029
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 →
20250.000.000.23
20260.000.000.23
20270.000.000.23
20280.000.000.23
20290.000.000.23

Wilson's Warbler Survey Routes in Utah

Routes recording Wilson'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 →
Moon Lake 2320162016
La Sal319931993
Goose Creek Mtn.320072002
Newcastle320222022
Notom319891989
Beck219741974
Lynn220111998
Soapstone220072002
Kamas220112011
Heber Mtn.220122001
Ant Flat-Ogden Can220211995
Uintah Nf219911991
Wasatch Nf220241988
Hyrum119771976
Altonah120061995
Grizzly Rdge120242024
Bryce Canyon119941993
Beaver119911991
Hanksville120112011
Navajo Lake120111990
Moon Lake120022002
Skyline Driv120072007
Richfield120182018
Gooseberry120241996
Hanna120112005

Wilson's Warbler Population Trend in Other States

alaskacaliforniacoloradoidahomainemichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorkoregonvermontwashingtonwisconsinwyoming

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