BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Swainson's Hawk In Great Basin

All regionsGreat BasinBirds of prey

Swainson's Hawk in Great Basin has surged: up 308% on the route-weighted index since 1970.

+308%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 →
175Routes 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 →

Swainson's Hawk has surged in Great Basin: up 308% 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 27% by 2030 — from 1.2 in 2025 to a central estimate of 1.5 (95% range 1.0–1.9). A 5-year backtest shows a typical error of ±20%, with 60% of held-out values landing inside the 95% band.

+27%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 →
1.5Projected 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 →
1.0–1.995% 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 →
±20%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 27% by 2030 — from 1.2 in 2025 to a central estimate of 1.5 (95% range 1.0–1.9). A 5-year backtest shows a typical error of ±20%, 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 →
20261.40.951.8
20271.40.971.8
20281.40.991.9
20291.41.01.9
20301.51.01.9

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
RirieIDAHO152025
DuboisIDAHO122025
BatesIDAHO122023
Cedar HillIDAHO122024
Mud LakeIDAHO112025
JosephOREGON72025
KeystoneWASHINGTON72025
Scootney ReservoirWASHINGTON72025
Columbia NwrWASHINGTON62022
SquirrelIDAHO52024
Blacks CreekIDAHO52017
MontagueOREGON52025
Blitzen 2OREGON52025
Green Mtn.OREGON52025
MerrillOREGON52022
HattonWASHINGTON51994
SulphurWASHINGTON52022
PrestonIDAHO42023
Majors PlaceNEVADA42024
Ruby Valley 2NEVADA42017
Alvord LakeOREGON42025
SheavilleOREGON42025

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