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

Wood Duck Population Trend in Maryland

All statesWaterfowl

Wood Duck in Maryland has surged: up 329% on the route-weighted index since 1968.

+329%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 →
69Routes 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 →
58YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Wood Duck Trends in MarylandNotable 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 increasecomputed 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 →

Wood Duck has surged in Maryland: up 329% on the route-weighted index since 1968.

Wood Duck Population Forecast in Maryland

If the recent trend holds, Wood Duck in Maryland is projected to rise about 20% by 2029 — from 0.57 in 2024 to a central estimate of 0.69 (95% range 0.33–1.0). A 5-year backtest shows a typical error of ±15.5%, with 100% of held-out values landing inside the 95% band.

+20%Change by 2029TrendPercent 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 →
0.69Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.33–1.095% 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 →
±15.5%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, Wood Duck in Maryland is projected to rise about 20% by 2029 — from 0.57 in 2024 to a central estimate of 0.69 (95% range 0.33–1.0). A 5-year backtest shows a typical error of ±15.5%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.660.301.0
20260.660.311.0
20270.670.321.0
20280.680.321.0
20290.690.331.0

Wood Duck Survey Routes in Maryland

Routes recording Wood Duck in Maryland.
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 →
Piney Neck1220231972
Nottingham1120222010
Mt Nebo919691969
Honga820241966
Madison820241976
Largo519781978
Oldtown420121974
Potomac Park420231993
Berlin420051991
Hughesville420011996
Vindex319961984
La Plata319811974
Newark320041982
Grove Neck319961995
Forest Grove320142013
Indiantown320141980
Wolfsville220191970
Olney220241975
Pleasant Val219961972
Upper Xrds219831974
Jones219901990
Cheltenham219901972
Pomfret220231972
Theodore220111972
Jennings220192000

Wood Duck Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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