BirdAnalyst
Species · Kansas · BBS 2025 Release · 1966–2024

Northern Harrier Population Trend in Kansas

All statesGeneralists

Northern Harrier in Kansas has collapsed: down 96% on the route-weighted index since 1969.

-96%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 →
46Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Northern Harrier Trends in KansasNotable 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 declinecomputed 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 →

Northern Harrier has collapsed in Kansas: down 96% on the route-weighted index since 1969.

Northern Harrier Population Forecast in Kansas

If the recent trend holds, Northern Harrier in Kansas is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±70.9%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.4095% 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 →
±70.9%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 Kansas is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.40). A 5-year backtest shows a typical error of ±70.9%, 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 →
20250.000.000.41
20260.000.000.40
20270.000.000.40
20280.000.000.40
20290.000.000.40

Northern Harrier Survey Routes in Kansas

Routes recording Northern Harrier in Kansas.
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 →
Hays520081969
Rexford420072000
Covert320041969
Hopewell320112003
Lapland219821976
Ashland220051997
Albert219971971
Wallace220171967
Leoville220121967
Rock Creek220021990
Ruleton220141981
Plymell220112000
Melrose119871970
Galesburg119691969
Humboldt120091986
Thrall119671967
Dalton120001968
St John119871967
Coats119671967
Coldwater120041979
Lakin120221967
Barclay119671967
Ellinor119851985
Buckeye120021970
Kanopolis120181972

Northern Harrier Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradodelawaregeorgiaidahoillinoisindianaiowakentuckylouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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