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

American Bittern Population Trend in Michigan

All statesWetland birds

American Bittern in Michigan has increased: up 48% on the route-weighted index since 1968.

+48%Since 1968TrendPercent 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 →
61Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable American Bittern Trends in MichiganNotable 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 American Bittern in Michigan. See the full index history below.

American Bittern Population Forecast in Michigan

If the recent trend holds, American Bittern in Michigan is projected to rise about 232% by 2029 — from 0.11 in 2024 to a central estimate of 0.35 (95% range 0.03–0.68). A 5-year backtest shows a typical error of ±64.4%, with 80% of held-out values landing inside the 95% band.

+232%Change 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 →
0.35Projected 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 →
0.03–0.6895% 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 →
±64.4%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, American Bittern in Michigan is projected to rise about 232% by 2029 — from 0.11 in 2024 to a central estimate of 0.35 (95% range 0.03–0.68). A 5-year backtest shows a typical error of ±64.4%, with 80% of held-out values landing inside the 95% band.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 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 →
20250.340.020.67
20260.340.020.67
20270.350.020.67
20280.350.020.68
20290.350.030.68

American Bittern Survey Routes in Michigan

Routes recording American Bittern in Michigan.
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 →
Seney Nwr1320191992
Pickford1120191973
No Bradley420152015
Crystal Fls320231983
Monterey320232023
Raco320241971
Marenisco220161988
Ned Lake220241997
Herman220132013
Gibbs City220191979
Cunard219831979
Shingleton220031967
Bravo220212021
Muskallonge220141968
Gilchrist219801976
Lake City220061971
Skeels219691967
Oberlin219741973
Cathro220131971
Beaver Lake219841974
Drayton Plns219751974
Ontonagon120172014
Bergland120181982
Bootjack119981969
Maple Grove120221968

American Bittern Population Trend in Other States

alaskacaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamainemarylandmassachusettsminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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