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

Mallard Population Trend in Maine

All statesWaterfowl

Mallard in Maine has surged: up 14× on the route-weighted index since 1972.

14×Since 1972TrendPercent 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 →
52Routes 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 →
51YearsYears 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 MaineNotable 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 →

Mallard has surged in Maine: up 14× on the route-weighted index since 1972.

Mallard Population Forecast in Maine

If the recent trend holds, Mallard in Maine is projected to rise about 28% by 2029 — from 1.4 in 2024 to a central estimate of 1.8 (95% range 0.65–2.9). A 5-year backtest shows a typical error of ±68.4%, with 20% of held-out values landing inside the 95% band.

+28%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 →
1.8Projected 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 →
0.65–2.995% 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 →
±68.4%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 Maine is projected to rise about 28% by 2029 — from 1.4 in 2024 to a central estimate of 1.8 (95% range 0.65–2.9). A 5-year backtest shows a typical error of ±68.4%, with 20% of held-out values landing inside the 95% band.19672029
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 →
20251.60.522.7
20261.70.552.8
20271.70.582.8
20281.70.622.8
20291.80.652.9

Mallard Survey Routes in Maine

Routes recording Mallard in Maine.
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 →
Manchester4219951977
Greenwood820241974
Turner620101990
Cape Neddick520221978
Boundary520151995
Kittery Pt420241973
Hartford420241992
Harmony420241988
Hermon420192006
Warren319851985
Brooks320131996
Hancock320241978
Newcastle220081989
Reeds220221998
South Arm220121984
Aurora220172009
Deblois219801980
Charleston220161995
Greenville220221998
Cambridge220081998
Forest Sta219671967
Lake Moxie220222009
Horse Mtn220012001
Westbrook120081990
Biddeford120181987

Mallard Population Trend in Other States

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

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