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

Northern Harrier Population Trend in Iowa

All statesGeneralists

Northern Harrier in Iowa has edged up: up 14% on the route-weighted index since 1982.

+14%Since 1982
19Routes In State
24Years

Notable Northern Harrier Trends in Iowa

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

Northern Harrier Population Forecast in Iowa

If the recent trend holds, Northern Harrier in Iowa is projected to stay roughly flat through 2027, near 0.07 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±79.3%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027
0.07Projected 2027 index
0.00–0.1795% range
±79.3%Backtest error
19682027
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
20230.070.000.17
20240.070.000.17
20250.070.000.17
20260.070.000.17
20270.070.000.17

Northern Harrier Survey Routes in Iowa

Routes recording Northern Harrier in Iowa.
Cedar Valley319901982
Wales219991999
Garner219901987
Mt Hamill119851985
Exline120042004
Melrose120052002
Bedford119991999
Bryant120061990
Brooklyn120102010
Red Rock119891989
Prairieburg120181968
Hudson120212021
Kanawha120182004
Washta119831983
Festina120031993
Davis Corner120221987
Gaza120092009
Rock Valley119881972
Tipton120082008

Northern Harrier Population Trend in Other States

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

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