BirdAnalyst
Species · New Jersey · BBS 2025 Release · 1966–2024

American Black Duck Population Trend in New Jersey

All statesWaterfowl

American Black Duck in New Jersey has collapsed: down 81% on the route-weighted index since 1968.

-81%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 →
19Routes 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 →
44YearsYears 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 New JerseyNotable 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 New Jersey: down 81% on the route-weighted index since 1968.

American Black Duck Population Forecast in New Jersey

If the recent trend holds, American Black Duck in New Jersey is projected to fall about 100% by 2027 — from 0.08 in 2022 to a central estimate of 0.00 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±87.8%, with 100% of held-out values landing inside the 95% band.

-100%Change by 2027TrendPercent 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 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.4195% 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 →
±87.8%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 New Jersey is projected to fall about 100% by 2027 — from 0.08 in 2022 to a central estimate of 0.00 (95% range 0.00–0.41). A 5-year backtest shows a typical error of ±87.8%, with 100% of held-out values landing inside the 95% band.19662027
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 →
20230.020.000.44
20240.020.000.43
20250.010.000.42
20260.000.000.42
20270.000.000.41

American Black Duck Survey Routes in New Jersey

Routes recording American Black Duck in New Jersey.
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 →
Bennett Mill519721967
Six Points420081978
Spraguetown419971982
Toms River219971974
Masonville219681968
New Bedford219741974
Croton219921992
Ocean City220221979
Mt Misery219871987
Pedricktown 2220132013
Cape May Ch220011992
Woodbury Hgt119701970
Greenwich120141968
Deepwater119771969
Albion119891971
Midvale119751967
Kemah Lake119771966
Villas119791979
Winslow119901990

American Black Duck Population Trend in Other States

alabamaconnecticutdelawareindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandvermontvirginiawest-virginiawisconsin

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