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

Northern Harrier Population Trend in Ohio

All statesGeneralists

Northern Harrier in Ohio has held roughly steady: up 7% on the route-weighted index since 1971.

+7%Since 1971TrendPercent 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 →
31Routes 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 →
31YearsYears 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 OhioNotable 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 Ohio. See the full index history below.

Northern Harrier Population Forecast in Ohio

If the recent trend holds, Northern Harrier in Ohio is projected to stay roughly flat through 2028, near 0.06 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±106.4%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.06Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1495% 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 →
±106.4%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 Ohio is projected to stay roughly flat through 2028, near 0.06 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±106.4%, with 100% of held-out values landing inside the 95% band.19662028
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 →
20240.060.000.14
20250.060.000.14
20260.060.000.14
20270.060.000.14
20280.060.000.14

Northern Harrier Survey Routes in Ohio

Routes recording Northern Harrier in Ohio.
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 →
Napoleon319961986
Bloomville320011997
Cosmos219961996
W Carrollton220042004
London220052005
Winterset219671967
Lockport120231975
Kunkle120131993
N Baltimore119961974
Pittsfield120171998
Peru119711966
Bismark119921992
Stonecreek120021996
Lenox120131993
Herner Crns120031998
Birmingham120112011
Kalida120112011
Petersburg119991999
No Kenton120171967
Marion119911991
New Dover120001994
Port William120172017
Dresden120011996
Cuba120112006
Xenia120172004

Northern Harrier Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradodelawaregeorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaoklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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