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

Swainson's Hawk Population Trend in Montana

All statesGeneralists

Swainson's Hawk in Montana has surged: up 644% on the route-weighted index since 1970.

+644%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 →
77Routes 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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Swainson's Hawk Trends in MontanaNotable 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 →

Swainson's Hawk has surged in Montana: up 644% on the route-weighted index since 1970.

Swainson's Hawk Population Forecast in Montana

If the recent trend holds, Swainson's Hawk in Montana is projected to stay roughly flat through 2029, near 1.1 (95% range 0.47–1.6). A 5-year backtest shows a typical error of ±16.4%, with 100% of held-out values landing inside the 95% band.

+2%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 →
1.1Projected 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 →
0.47–1.695% 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 →
±16.4%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, Swainson's Hawk in Montana is projected to stay roughly flat through 2029, near 1.1 (95% range 0.47–1.6). A 5-year backtest shows a typical error of ±16.4%, with 100% 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 →
20251.00.431.6
20261.00.441.6
20271.00.451.6
20281.00.461.6
20291.10.471.6

Swainson's Hawk Survey Routes in Montana

Routes recording Swainson's Hawk in Montana.
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 →
Circle1020211969
Whitlash1020242009
Hay Lake820221988
Redstone720241969
Harlem620211981
Westby620242015
Virgelle520241979
Cleveland520241979
Church Hill520242017
Malta420241976
St. Mary 2420232010
Shelby420242015
Sunburst320071970
Oswego320231978
Great Falls320241973
Flatwillow320061968
Webster320241980
Red Rock320231988
Glentana320242015
Wheat Basin320242017
Chuffey Spring320192016
Glasgow220241970
Roy220231988
Brusett220112001
Jordan220241982

Swainson's Hawk Population Trend in Other States

arizonaarkansascaliforniacoloradoidahoillinoisiowakansaslouisianaminnesotamissourinebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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