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

Least Bittern Population Trend in Michigan

All statesWetland birds

Least Bittern in Michigan has fallen sharply: down 53% on the route-weighted index since 1978.

-53%Since 1978TrendPercent 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 →
9Routes 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 →
12YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Least 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 Least Bittern in Michigan. See the full index history below.

Least Bittern Survey Routes in Michigan

Routes recording Least 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 →
Nashville119981978
Coopersville120042004
Galesburg119801970
Pettysville119761976
Monterey119951995
Chippewa Lk.120062006
Pickford119791979
Brocky Lake120222022
Lake City120142014

Least Bittern Population Trend in Other States

alabamaarizonaarkansascaliforniaconnecticutdelawarefloridageorgiaillinoisindianaiowakansaslouisianamarylandminnesotamississippimissourinebraskanevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooregonsouth-carolinasouth-dakotatexasvermontvirginiawisconsin

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