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

American Bittern Population Trend in Wisconsin

All statesWetland birds

American Bittern in Wisconsin has declined: down 31% on the route-weighted index since 1968.

-31%Since 1968
71Routes In State
58Years

Notable American Bittern Trends in Wisconsin

No notable trend signals for American Bittern in Wisconsin. See the full index history below.

American Bittern Population Forecast in Wisconsin

If the recent trend holds, American Bittern in Wisconsin is projected to fall about 22% by 2029 — from 0.07 in 2024 to a central estimate of 0.06 (95% range 0.00–0.35). A 5-year backtest shows a typical error of ±25.3%, with 100% of held-out values landing inside the 95% band.

-22%Change by 2029
0.06Projected 2029 index
0.00–0.3595% range
±25.3%Backtest error
19662029
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
20250.080.000.38
20260.080.000.37
20270.070.000.37
20280.060.000.36
20290.060.000.35

American Bittern Survey Routes in Wisconsin

Routes recording American Bittern in Wisconsin.
Phillips520221967
Couderay420171969
Holway419831968
Pardeeville419991970
Shanagolden319941977
Elderon320161981
Weirgor Springs320172004
Land O' Lakes 2320222021
Chaffey219921990
Land O Lakes220041979
Rib Lake220171966
Mcnaughton219921967
Mather220231969
Wis Rapids220171969
Omro220001966
Flambeau220081998
Fall River220041970
Cavour220242014
Beaver Dam220041969
Briggsville220192000
Iron River120091985
Minong120181977
Grand View119921992
Bayfield119941967
Montreal119941988

American Bittern Population Trend in Other States

alaskacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwest-virginiawyoming

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