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Species · Idaho · BBS 2026 Release · 1966–2025

Swainson's Hawk Population Trend in Idaho

All statesBirds of prey

Swainson's Hawk in Idaho has surged: up 381% on the route-weighted index since 1972.

+381%Since 1972TrendPercent 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 →
37Routes 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 →
53YearsYears 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 IdahoNotable 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 Idaho: up 381% on the route-weighted index since 1972.

Swainson's Hawk Population Forecast in Idaho

If the recent trend holds, Swainson's Hawk in Idaho is projected to rise about 80% by 2030 — from 1.6 in 2025 to a central estimate of 2.8 (95% range 1.6–4.1). A 5-year backtest shows a typical error of ±46.5%, with 60% of held-out values landing inside the 95% band.

+80%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 →
2.8Projected 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 →
1.6–4.195% 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 →
±46.5%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, Swainson's Hawk in Idaho is projected to rise about 80% by 2030 — from 1.6 in 2025 to a central estimate of 2.8 (95% range 1.6–4.1). A 5-year backtest shows a typical error of ±46.5%, with 60% of held-out values landing inside the 95% band.19682030
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 →
20262.61.43.9
20272.71.43.9
20282.71.54.0
20292.81.54.0
20302.81.64.1

Swainson's Hawk Survey Routes in Idaho

Routes recording Swainson's Hawk in Idaho.
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 →
Acequia2920121987
Picabo2120211990
Pocatello2020191980
Ririe1520251987
Dubois1220251972
Bates1220231988
Cedar Hill1220241990
Mud Lake1120251988
Squirrel520241972
Blacks Creek520171968
Preston420231988
Lost River320251986
Tractor Flat320251985
Craters320181979
Sawtooth City 2320232015
Crane Creek320191988
Daniels Res320251991
Mora320252018
Twin Buttes220251985
Kyle Canyon220241985
Cascade219821972
Springfield220181971
Triangle220212021
Henry219831979
Joel219991998

Swainson's Hawk Population Trend in Other States

alaskaarizonaarkansascaliforniacoloradoillinoisiowakansaslouisianaminnesotamissourimontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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