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

Swainson's Hawk Population Trend in Idaho

All statesGeneralists

Swainson's Hawk in Idaho has surged: up 622% on the route-weighted index since 1972.

+622%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 →
52YearsYears 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 622% 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 70% by 2029 — from 1.7 in 2024 to a central estimate of 2.9 (95% range 1.7–4.2). A 5-year backtest shows a typical error of ±41.1%, with 40% of held-out values landing inside the 95% band.

+70%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 →
2.9Projected 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 →
1.7–4.295% 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 →
±41.1%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, Swainson's Hawk in Idaho is projected to rise about 70% by 2029 — from 1.7 in 2024 to a central estimate of 2.9 (95% range 1.7–4.2). A 5-year backtest shows a typical error of ±41.1%, with 40% 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 →
20252.71.54.0
20262.81.54.0
20272.81.64.1
20282.91.64.1
20292.91.74.2

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
Mud Lake1420231988
Bates1220231988
Cedar Hill1220241990
Dubois1020241972
Twin Buttes920241985
Ririe620231987
Squirrel520241972
Blacks Creek520171968
Preston420231988
Tractor Flat320241985
Craters320181979
Sawtooth City 2320232015
Crane Creek320191988
Daniels Res320191991
Kyle Canyon220241985
Cascade219821972
Springfield220181971
Triangle220212021
Henry219831979
Joel219991998
Silver City220192019
Carey220141989

Swainson's Hawk Population Trend in Other States

arizonaarkansascaliforniacoloradoillinoisiowakansaslouisianaminnesotamissourimontananebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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