BirdAnalyst
Species · BCR 11 · BBS 2025 Release · 1966–2024

Ferruginous Hawk In Prairie Potholes

All regionsPrairie PotholesGeneralists

Ferruginous Hawk in Prairie Potholes has surged: up 448% on the route-weighted index since 1969.

+448%Since 1969TrendPercent 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 →
49Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 →

Ferruginous Hawk has surged in Prairie Potholes: up 447% on the route-weighted index since 1969.

Forecast

If the recent trend holds, Ferruginous Hawk in Prairie Potholes is projected to rise about 41% by 2029 — from 0.34 in 2024 to a central estimate of 0.48 (95% range 0.25–0.70). A 5-year backtest shows a typical error of ±47.2%, with 80% of held-out values landing inside the 95% band.

+41%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 →
0.48Projected 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 →
0.25–0.7095% 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 →
±47.2%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 Prairie Potholes is projected to rise about 41% by 2029 — from 0.34 in 2024 to a central estimate of 0.48 (95% range 0.25–0.70). A 5-year backtest shows a typical error of ±47.2%, with 80% of held-out values landing inside the 95% band.19672029
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 →
20250.450.230.68
20260.460.230.68
20270.470.240.69
20280.470.250.70
20290.480.250.70

Routes In Prairie Potholes

Routes recording Ferruginous Hawk in Prairie Potholes.
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 →
WhitlashMONTANA102024
Hay LakeMONTANA72022
MaltaMONTANA62024
GlentanaMONTANA32024
Crow CreekSOUTH-DAKOTA32010
GettysburgSOUTH-DAKOTA32000
VirgelleMONTANA22024
HarlemMONTANA22021
OswegoMONTANA22024
GildfordMONTANA22019
Sun RiverMONTANA22018
DanzigNORTH-DAKOTA22010
Sheyenne LkNORTH-DAKOTA22002
Long LakeSOUTH-DAKOTA22013
GormanSOUTH-DAKOTA21980
SunburstMONTANA12007
ClevelandMONTANA12017
GlasgowMONTANA11994
RedstoneMONTANA12016
Great FallsMONTANA12022
ShelbyMONTANA12022
ChinookMONTANA12022
Ester LakeMONTANA12018
SacoMONTANA12021
LambertMONTANA12024

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