BirdAnalyst
Species · Vermont · BBS 2026 Release · 1966–2025

Mallard Population Trend in Vermont

All statesWaterfowl

Mallard in Vermont has surged: up 49× on the route-weighted index since 1970.

49×Since 1970TrendPercent 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 →
24Routes 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 VermontNotable 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 Vermont: up 49× on the route-weighted index since 1970.

Mallard Population Forecast in Vermont

If the recent trend holds, Mallard in Vermont is projected to fall about 47% by 2030 — from 4.6 in 2025 to a central estimate of 2.4 (95% range 0.62–4.2). A 5-year backtest shows a typical error of ±49.4%, with 60% of held-out values landing inside the 95% band.

-47%Change by 2030TrendPercent 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 →
2.4Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.62–4.295% 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 →
±49.4%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 Vermont is projected to fall about 47% by 2030 — from 4.6 in 2025 to a central estimate of 2.4 (95% range 0.62–4.2). A 5-year backtest shows a typical error of ±49.4%, with 60% of held-out values landing inside the 95% band.19672030
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 →
20262.20.464.0
20272.30.504.1
20282.30.544.1
20292.40.584.1
20302.40.624.2

Mallard Survey Routes in Vermont

Routes recording Mallard in Vermont.
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 →
Fletcher7520231990
Landgrove4120251997
W Rutland1320251974
Gaysville820251986
Grand Isle720251967
Middlesex620251990
Hinesburg419911977
Marlboro220241972
S Reading220191993
Shaftsbury220131990
S Wallingfrd220181973
Greensboro220251995
Stowe220101998
Bristol220141998
North Pownal120251974
Stratton120252015
Post Mills120241967
St Johnsbury120231998
East Haven120221987
Northfld Fls120251986
East Calais120251974
Hardwick120131978
Colchester120251989
Newbury 2120232012

Mallard Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.