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Species · Michigan · BBS 2025 Release · 1966–2024

American Black Duck Population Trend in Michigan

All statesWaterfowl

American Black Duck in Michigan has fallen sharply: down 56% on the route-weighted index since 1971.

-56%Since 1971TrendPercent 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 →
27Routes 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 →
37YearsYears 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 Black Duck 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 →

American Black Duck has fallen sharply in Michigan: down 56% on the route-weighted index since 1971.

American Black Duck Population Forecast in Michigan

If the recent trend holds, American Black Duck in Michigan is projected to stay roughly flat through 2021, near 0.01 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±31.8%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2021TrendPercent 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 →
0.01Projected 2021 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 →
±31.8%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 Black Duck in Michigan is projected to stay roughly flat through 2021, near 0.01 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±31.8%, with 100% of held-out values landing inside the 95% band.19692021
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 →
20170.020.000.23
20180.020.000.22
20190.020.000.22
20200.010.000.22
20210.010.000.21

American Black Duck Survey Routes in Michigan

Routes recording American Black Duck 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 →
S Lyons1119771977
Beaver Lake319811981
Ned Lake219861986
Herman219911991
Irons219791979
Skegemog Pt220111974
Galesburg219891973
Howardsville219691969
Cathro219701970
Ontonagon119721972
Bergland119931993
Crystal Fls120092009
Seney Nwr120161995
Wilson120031969
Bear Lake119721972
Scottville119741971
Tahquamenon119791979
Gilchrist119961979
Pleasant Val119851985
Belding119911991
Mottville119761976
Pickford120001973
Walloon Lake119771977
Frederic119901990
St Charles119761976

American Black Duck Population Trend in Other States

alabamaconnecticutdelawareindianamainemarylandmassachusettsminnesotanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandvermontvirginiawest-virginiawisconsin

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