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Species · Wisconsin · BBS 2025 Release · 1966–2024

American Black Duck Population Trend in Wisconsin

All statesWaterfowl

American Black Duck in Wisconsin has collapsed: down 77% on the route-weighted index since 1968.

-77%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 →
22Routes 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 →
32YearsYears 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 WisconsinNotable 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 collapsed in Wisconsin: down 77% on the route-weighted index since 1968.

American Black Duck Population Forecast in Wisconsin

If the recent trend holds, American Black Duck in Wisconsin is projected to stay roughly flat through 2015, near 0.02 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±139.1%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2015TrendPercent 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 →
0.02Projected 2015 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.2095% 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 →
±139.1%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 Wisconsin is projected to stay roughly flat through 2015, near 0.02 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±139.1%, with 100% of held-out values landing inside the 95% band.19662015
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 →
20110.030.000.20
20120.020.000.20
20130.020.000.20
20140.020.000.20
20150.020.000.20

American Black Duck Survey Routes in Wisconsin

Routes recording American Black Duck in Wisconsin.
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 →
Elderon320092009
Exeland219991968
Gilman220051975
Irma219871968
Stevens Pt219961996
Oconto Falls219921992
Omro220001975
Brownsville219751975
Rolling Pr219821972
Pt Washingtn220082000
Minong119741974
Shanagolden119861975
Land O Lakes119741974
Weyerhauser119751968
Couderay120101975
Eagle River119751966
Washington I119711967
Mather119921976
Manawa119801980
Manitowoc119941993
Casco120021978
Bashaw120042004

American Black Duck Population Trend in Other States

alabamaconnecticutdelawareindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandvermontvirginiawest-virginia

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