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

Black-headed Grosbeak Population Trend in Utah

All statesGeneralists

Black-headed Grosbeak in Utah has surged: up 205% on the route-weighted index since 1970.

+205%Since 1970TrendPercent 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 →
78Routes 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 →
51YearsYears 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-headed Grosbeak 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 →

Black-headed Grosbeak has surged in Utah: up 205% on the route-weighted index since 1970.

Black-headed Grosbeak Population Forecast in Utah

If the recent trend holds, Black-headed Grosbeak in Utah is projected to rise about 15% by 2029 — from 1.7 in 2024 to a central estimate of 1.9 (95% range 1.2–2.7). A 5-year backtest shows a typical error of ±35.5%, with 80% of held-out values landing inside the 95% band.

+15%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 →
1.9Projected 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 →
1.2–2.795% 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 →
±35.5%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, Black-headed Grosbeak in Utah is projected to rise about 15% by 2029 — from 1.7 in 2024 to a central estimate of 1.9 (95% range 1.2–2.7). A 5-year backtest shows a typical error of ±35.5%, with 80% 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 →
20251.81.12.6
20261.91.12.6
20271.91.12.6
20281.91.22.7
20291.91.22.7

Black-headed Grosbeak Survey Routes in Utah

Routes recording Black-headed Grosbeak 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 →
Main Canyon1820241989
Moab1420241986
Aneth1120241993
Beck 21020181990
Ant Flat-Ogden Can920231994
La Sal 2920062003
Beck819871971
Hardware Ranch820231994
Monticello820241999
Moon Lake 2720232004
Navajo Lake620241969
Jensen620242002
Gooseberry620241994
Newcastle620221997
Alton620111997
La Sal 3620242007
Beaver520241968
Uintah Nf519941990
Richfield520191994
Kamas520192005
Fayette420211993
Heber Mtn.420221996
Pine Creek420102010
Moquith Mtn320011997
Moon Lake320021995

Black-headed Grosbeak Population Trend in Other States

alaskaarizonacaliforniacoloradoidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexaswashingtonwyoming

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