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

Ferruginous Hawk Population Trend in Utah

All statesGeneralists

Ferruginous Hawk in Utah has fallen sharply: down 60% on the route-weighted index since 1979.

-60%Since 1979TrendPercent 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 →
44Routes 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 →
47YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Ferruginous Hawk 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 →

Ferruginous Hawk has fallen sharply in Utah: down 60% on the route-weighted index since 1979.

Ferruginous Hawk Population Forecast in Utah

If the recent trend holds, Ferruginous Hawk in Utah is projected to fall about 100% by 2029 — from 0.32 in 2024 to a central estimate of 0.00 (95% range 0.00–0.88). A 5-year backtest shows a typical error of ±139.7%, 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 →
0.00–0.8895% 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 →
±139.7%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, Ferruginous Hawk in Utah is projected to fall about 100% by 2029 — from 0.32 in 2024 to a central estimate of 0.00 (95% range 0.00–0.88). A 5-year backtest shows a typical error of ±139.7%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.000.000.88
20260.000.000.88
20270.000.000.88
20280.000.000.88
20290.000.000.88

Ferruginous Hawk Survey Routes in Utah

Routes recording Ferruginous Hawk 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 →
Snowville720242018
Beryl620241987
Pine Creek420182003
Salt Springs320191986
Grouse Creek320101983
Timpie Spg220011979
Neponset Res220181997
Dragerton220111989
Lynn220191996
Leamington220162003
Grantsville220222005
Westwater220241997
Jensen220241994
Fish Springs220151989
Cleveland219941994
Wendover119691969
Beck119691969
Saleratus Cr120121998
Notch Peak119921991
Oak City120241974
Goshen120111987
E. Bear Lake120222008
Stock Res120211986
Beaver120131974
Iron Springs120051984

Ferruginous Hawk Population Trend in Other States

arizonacaliforniacoloradoidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexaswashingtonwyoming

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