BirdAnalyst
Species · BCR 17 · BBS 2026 Release · 1966–2025

Northern Harrier In Badlands and Prairies

All regionsBadlands and PrairiesBirds of prey

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 →
58YearsYears 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 rise about 18% by 2030 — from 0.61 in 2025 to a central estimate of 0.72 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±34.1%, with 100% of held-out values landing inside the 95% band.

+18%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 →
0.72Projected 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 →
0.00–1.595% 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 →
±34.1%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 rise about 18% by 2030 — from 0.61 in 2025 to a central estimate of 0.72 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±34.1%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20260.770.001.6
20270.760.001.6
20280.750.001.6
20290.730.001.5
20300.720.001.5

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 →
Wheat BasinMONTANA52025
SolenNORTH-DAKOTA52024
HardingSOUTH-DAKOTA52025
CircleMONTANA42023
Coleman CouleeMONTANA42024
Chuffey SpringMONTANA42024
Winifred 2MONTANA42025
CarsonNORTH-DAKOTA42024
SussexWYOMING42016
ShawneeWYOMING42003
Gvnt ValleyWYOMING42019
JordanMONTANA32017
LindsayMONTANA32024
CrookstonNEBRASKA32019
Oglala Nat. Grass.NEBRASKA32015
LarkNORTH-DAKOTA31986
ZapNORTH-DAKOTA32024
RavenWYOMING32025
HighwoodMONTANA22024
RoyMONTANA22025
BrusettMONTANA22024
IngomarMONTANA22025
ForsythMONTANA22019
LocateMONTANA22024
WebsterMONTANA22024

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