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

Bendire's Thrasher Population Trend in Utah

All statesGeneralists

Bendire's Thrasher in Utah has collapsed: down 98% on the route-weighted index since 1984.

-98%Since 1984TrendPercent 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 →
8Routes 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 →
20YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bendire's Thrasher 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 →

Bendire's Thrasher has collapsed in Utah: down 98% on the route-weighted index since 1984.

Bendire's Thrasher Population Forecast in Utah

If the recent trend holds, Bendire's Thrasher in Utah is projected to stay roughly flat through 2017, near 0.00 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±1868%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2017TrendPercent 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 2017 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.4895% 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 →
±1868%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, Bendire's Thrasher in Utah is projected to stay roughly flat through 2017, near 0.00 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±1868%, with 100% of held-out values landing inside the 95% band.19812017
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 →
20130.000.000.48
20140.000.000.48
20150.000.000.48
20160.000.000.48
20170.000.000.48

Bendire's Thrasher Survey Routes in Utah

Routes recording Bendire's Thrasher 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 →
Cane Spr Des319991998
Leamington219941994
Shivwitz220041992
Dixie Nf219951995
Lake Powell120072007
Iron Springs120121981
Glen Canyon120111994
Blanding120001996

Bendire's Thrasher Population Trend in Other States

arizonacalifornianevadanew-mexico

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