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Species · Michigan · BBS 2025 Release · 1966–2024

Common Gallinule Population Trend in Michigan

All statesWetland birds

Common Gallinule in Michigan has collapsed: down 86% on the route-weighted index since 1973.

-86%Since 1973TrendPercent 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 →
7Routes 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 →
20YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Common Gallinule 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 →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Common Gallinule has collapsed in Michigan: down 86% on the route-weighted index since 1973.

Common Gallinule Population Forecast in Michigan

If the recent trend holds, Common Gallinule in Michigan is projected to stay roughly flat through 2018, near 0.00 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±126.4%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2018TrendPercent 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 →
0.00Projected 2018 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.1195% 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 →
±126.4%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, Common Gallinule in Michigan is projected to stay roughly flat through 2018, near 0.00 (95% range 0.00–0.11). A 5-year backtest shows a typical error of ±126.4%, with 100% of held-out values landing inside the 95% band.19702018
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 →
20140.000.000.11
20150.000.000.11
20160.000.000.11
20170.000.000.11
20180.000.000.11

Common Gallinule Survey Routes in Michigan

Routes recording Common Gallinule 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 →
North Branch219881988
Nashville119811976
Belding119881988
Galesburg120131970
Chippewa Lk.120001992
Skeels119801980
Bravo119831983

Common Gallinule Population Trend in Other States

alabamaarizonaarkansascaliforniaconnecticutdelawarefloridageorgiaillinoisindianakansaskentuckylouisianamainemarylandmassachusettsminnesotamississippinevadanew-jerseynew-yorknorth-carolinaohiopennsylvaniasouth-carolinatennesseetexasutahvermontwisconsin

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