BirdAnalyst
Species · BCR 17 · BBS 2025 Release · 1966–2024

Northern Harrier In Badlands and Prairies

All regionsBadlands and PrairiesGeneralists

Northern Harrier in Badlands and Prairies has declined: down 44% on the route-weighted index since 1969.

-44%Since 1969TrendPercent 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 →
115Routes 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 →

No notable trend signals for Northern Harrier in Badlands and Prairies. See the full index history below.

Northern Harrier In Badlands and Prairies Population Forecast

If the recent trend holds, Northern Harrier in Badlands and Prairies is projected to fall about 41% by 2029 — from 1.3 in 2024 to a central estimate of 0.74 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±32.1%, with 100% of held-out values landing inside the 95% band.

-41%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 →
0.74Projected 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 →
0.00–1.695% 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 →
±32.1%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, Northern Harrier in Badlands and Prairies is projected to fall about 41% by 2029 — from 1.3 in 2024 to a central estimate of 0.74 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±32.1%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.800.001.6
20260.780.001.6
20270.770.001.6
20280.760.001.6
20290.740.001.6

Routes In Badlands and Prairies

Routes recording Northern Harrier in Badlands and Prairies.
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 →
Two DotMONTANA92024
GorhamNORTH-DAKOTA52018
SolenNORTH-DAKOTA52024
CircleMONTANA42023
ShawmutMONTANA42024
Wheat BasinMONTANA42024
Chuffey SpringMONTANA42024
CarsonNORTH-DAKOTA42024
HardingSOUTH-DAKOTA42019
RevaSOUTH-DAKOTA42024
LodgepoleSOUTH-DAKOTA42023
SussexWYOMING42016
ShawneeWYOMING42003
Gvnt ValleyWYOMING42019
JordanMONTANA32017
LindsayMONTANA32024
CrookstonNEBRASKA32019
Oglala Nat. Grass.NEBRASKA32015
LarkNORTH-DAKOTA31986
ZapNORTH-DAKOTA32024
Fort PierreSOUTH-DAKOTA32024
MaurineSOUTH-DAKOTA32024
HighwoodMONTANA22024
RoyMONTANA22024
BrusettMONTANA22024

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