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

Northern Harrier In Great Basin

All regionsGreat BasinGeneralists

Northern Harrier in Great Basin has edged up: up 10% on the route-weighted index since 1970.

+10%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 →
214Routes 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 →

No notable trend signals for Northern Harrier in Great Basin. See the full index history below.

Northern Harrier In Great Basin Population Forecast

If the recent trend holds, Northern Harrier in Great Basin is projected to stay roughly flat through 2029, near 0.98 (95% range 0.41–1.5). A 5-year backtest shows a typical error of ±49.9%, with 80% of held-out values landing inside the 95% band.

-5%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 →
0.98Projected 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 →
0.41–1.595% 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 →
±49.9%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, Northern Harrier in Great Basin is projected to stay roughly flat through 2029, near 0.98 (95% range 0.41–1.5). A 5-year backtest shows a typical error of ±49.9%, with 80% 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 →
20250.970.411.5
20260.970.411.5
20270.970.411.5
20280.980.411.5
20290.980.411.5

Routes In Great Basin

Routes recording Northern Harrier 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 →
SnowvilleUTAH142024
HikoNEVADA92016
Flook LakeOREGON92024
PromontoryUTAH92024
DorrisCALIFORNIA82019
MidasNEVADA82012
Walla WallaWASHINGTON81993
Ruby Valley 2NEVADA72024
PrincetonOREGON61985
PomonaWASHINGTON61999
DuboisIDAHO52024
PendletonOREGON52024
Blitzen 2OREGON52024
WilburWASHINGTON52021
Davis CreekCALIFORNIA41998
LeadoreIDAHO42024
Glenns FerryIDAHO41986
Harney LakeOREGON42024
Warner VallyOREGON42024
Bowden HillsOREGON42024
Johnson CanUTAH42024
Goose Creek Mtn.UTAH42009
EwanWASHINGTON42019
PotholesWASHINGTON42019
IngallsCALIFORNIA32000

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