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

Mallard Population Trend in Maryland

All statesWaterfowl

Mallard in Maryland has increased: up 29% on the route-weighted index since 1968.

+29%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 →
74Routes 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 Mallard 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 →

No notable trend signals for Mallard in Maryland. See the full index history below.

Mallard Population Forecast in Maryland

If the recent trend holds, Mallard in Maryland is projected to rise about 254% by 2029 — from 0.79 in 2024 to a central estimate of 2.8 (95% range 0.00–6.2). A 5-year backtest shows a typical error of ±321.7%, with 100% of held-out values landing inside the 95% band.

+254%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 →
2.8Projected 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 →
0.00–6.295% 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 →
±321.7%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, Mallard in Maryland is projected to rise about 254% by 2029 — from 0.79 in 2024 to a central estimate of 2.8 (95% range 0.00–6.2). A 5-year backtest shows a typical error of ±321.7%, 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 →
20252.70.006.2
20262.80.006.2
20272.80.006.2
20282.80.006.2
20292.80.006.2

Mallard Survey Routes in Maryland

Routes recording Mallard 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 →
Honga1420241966
Smithsburg1320141970
Fair Hill1319961992
Oldtown919781978
Beltsville920121973
La Plata720091968
St. George'S Island620172015
Island Creek620241992
Mt Nebo519911978
Vindex520081967
Broomes Isl519961969
Potomac Park420111995
Randallstown419981973
Van Bibber420061973
Northeast420161969
Golden Hill420181971
Madison420241966
Newark420181971
Green Ridge419971997
Berlin420161984
Upper Xrds320081969
Jones319941966
Pt Republic319741974
Harmony320171977
Easton320211971

Mallard Population Trend in Other States

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

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