BirdAnalyst
Species · South Dakota · BBS 2026 Release · 1966–2025

Ferruginous Hawk Population Trend in South Dakota

All statesBirds of prey

Ferruginous Hawk in South Dakota has surged: up 612% on the route-weighted index since 1973.

+612%Since 1973TrendPercent 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 →
32Routes 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 Ferruginous Hawk Trends in South DakotaNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Ferruginous Hawk in South Dakota. See the full index history below.

Ferruginous Hawk Population Forecast in South Dakota

If the recent trend holds, Ferruginous Hawk in South Dakota is projected to rise about 44% by 2030 — from 0.14 in 2025 to a central estimate of 0.21 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±103.1%, with 80% of held-out values landing inside the 95% band.

+44%Change by 2030TrendPercent 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 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.4195% 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 →
±103.1%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, Ferruginous Hawk in South Dakota is projected to rise about 44% by 2030 — from 0.14 in 2025 to a central estimate of 0.21 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±103.1%, with 80% of held-out values landing inside the 95% band.19692030
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 →
20260.200.000.40
20270.200.000.40
20280.200.000.41
20290.200.000.41
20300.210.000.41

Ferruginous Hawk Survey Routes in South Dakota

Routes recording Ferruginous Hawk in South Dakota.
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 →
Crow Creek320102009
Gettysburg320001992
Cottonwood220251994
S. Pioneer220242008
Long Lake220131977
Gorman219801980
Isabel220152009
Pioneer120211992
Geddes119971997
Rockyford120232016
Roswell119811981
Indian120251998
Railroad Butte120172017
Ft Thompson120071970
French Creek119961995
Forbes119861982
Promise120111996
Owanka120022002
Volunteer119881979
Ottumwa120041969
Harding120171973
Cedar Pass119781977
Fort Pierre119951980
Maurine120221980
Reva120251996

Ferruginous Hawk Population Trend in Other States

arizonacaliforniacoloradoidahokansasmontananebraskanevadanew-mexiconorth-dakotaoklahomaoregontexasutahwashingtonwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.