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

Great Horned Owl Population Trend in Wisconsin

All statesGeneralists

Great Horned Owl in Wisconsin has declined: down 26% on the route-weighted index since 1969.

-26%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 →
75Routes 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 →
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 Great Horned Owl Trends in WisconsinNotable 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 Great Horned Owl in Wisconsin. See the full index history below.

Great Horned Owl Population Forecast in Wisconsin

If the recent trend holds, Great Horned Owl in Wisconsin is projected to stay roughly flat through 2029, near 0.08 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±248%, 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 →
0.08Projected 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 →
0.00–0.2195% 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 →
±248%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, Great Horned Owl in Wisconsin is projected to stay roughly flat through 2029, near 0.08 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±248%, 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 →
20250.080.000.21
20260.080.000.21
20270.080.000.21
20280.080.000.21
20290.080.000.21

Great Horned Owl Survey Routes in Wisconsin

Routes recording Great Horned Owl in Wisconsin.
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 →
Princeton420111982
Weyerhauser320111994
Omro319991969
Beaver Dam320211991
Phillips220121980
Meridean220102010
Manitowoc220231967
Viroqua220101979
Kendall220011986
Rolling Pr220141983
Eden220181970
Wiota220061983
Hebron220211981
Kiel220061999
Buena Vista220191998
Bashaw220052005
Iron River120221983
Minong119881988
Flambeau120002000
Bayfield120012001
Shanagolden120002000
Montreal120041968
Land O Lakes119811970
Hudson119811972
Dresser120211977

Great Horned Owl Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawyoming

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