BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Swainson's Hawk In Great Basin

All regionsGreat BasinGeneralists

Swainson's Hawk in Great Basin has surged: up 369% on the route-weighted index since 1970.

+369%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 →
173Routes 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 →
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 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 →

Swainson's Hawk has surged in Great Basin: up 369% on the route-weighted index since 1970.

Swainson's Hawk In Great Basin Population Forecast

If the recent trend holds, Swainson's Hawk in Great Basin is projected to rise about 46% by 2029 — from 1.0 in 2024 to a central estimate of 1.5 (95% range 1.0–1.9). A 5-year backtest shows a typical error of ±24.7%, with 40% of held-out values landing inside the 95% band.

+46%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 →
1.5Projected 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 →
1.0–1.995% 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 →
±24.7%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 Great Basin is projected to rise about 46% by 2029 — from 1.0 in 2024 to a central estimate of 1.5 (95% range 1.0–1.9). A 5-year backtest shows a typical error of ±24.7%, 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 →
20251.40.941.8
20261.40.961.8
20271.40.981.9
20281.41.01.9
20291.51.01.9

Routes In Great Basin

Routes recording Swainson's Hawk in Great Basin.
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 →
AcequiaIDAHO292012
PicaboIDAHO212021
PocatelloIDAHO202019
Mud LakeIDAHO142023
SnowvilleUTAH132024
BatesIDAHO122023
Cedar HillIDAHO122024
DuboisIDAHO102024
Twin ButtesIDAHO92024
UmatillaOREGON82023
KeystoneWASHINGTON82024
RirieIDAHO62023
Columbia NwrWASHINGTON62022
CedarvilleCALIFORNIA52024
SquirrelIDAHO52024
Blacks CreekIDAHO52017
MerrillOREGON52022
SheavilleOREGON52022
Trout CreekOREGON52021
HattonWASHINGTON51994
SulphurWASHINGTON52022
LikelyCALIFORNIA42024
PrestonIDAHO42023
Majors PlaceNEVADA42024
Ruby Valley 2NEVADA42017

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