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

Mallard Population Trend in New Hampshire

All statesWaterfowl

Mallard in New Hampshire has surged: up 203% on the route-weighted index since 1968.

+203%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 →
26Routes 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 →
56YearsYears 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 New HampshireNotable 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 New Hampshire: up 203% on the route-weighted index since 1968.

Mallard Population Forecast in New Hampshire

If the recent trend holds, Mallard in New Hampshire is projected to stay roughly flat through 2029, near 1.9 (95% range 0.83–3.1). A 5-year backtest shows a typical error of ±17.3%, with 100% of held-out values landing inside the 95% band.

-1%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 →
1.9Projected 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 →
0.83–3.195% 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 →
±17.3%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 New Hampshire is projected to stay roughly flat through 2029, near 1.9 (95% range 0.83–3.1). A 5-year backtest shows a typical error of ±17.3%, 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 →
20251.80.733.0
20261.90.753.0
20271.90.783.0
20281.90.803.0
20291.90.833.1

Mallard Survey Routes in New Hampshire

Routes recording Mallard in New Hampshire.
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 →
Epsom2320231980
Strafford1820241980
Franconia1120241986
Dover820241980
Peterborough519991984
Crawford Not519741967
Marlow420131990
Concord320151966
Wilmot320131991
Brentwood219971997
Fitzwilliam220241970
Canterbury220241978
Mt Chocorua219961973
Jefferson Hl220191992
Dixville Notch 2220182018
Hopkinton120091980
Gilmantn I W120171990
Walpole120231994
Lempster120231975
Milan120241978
Stratford120241978
Dixvil Notch120091988
Clarksville120231977
Glen120221991
East Kingston120231999

Mallard Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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