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

Mallard Population Trend in Delaware

All statesWaterfowl

Mallard in Delaware has surged: up 266% on the route-weighted index since 1969.

+266%Since 1969TrendPercent 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 →
15Routes 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 DelawareNotable 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 Delaware: up 266% on the route-weighted index since 1969.

Mallard Population Forecast in Delaware

If the recent trend holds, Mallard in Delaware is projected to fall about 16% by 2030 — from 7.0 in 2025 to a central estimate of 5.9 (95% range 0.00–12). A 5-year backtest shows a typical error of ±364.5%, with 100% of held-out values landing inside the 95% band.

-16%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 →
5.9Projected 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 →
0.00–1295% 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 →
±364.5%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, Mallard in Delaware is projected to fall about 16% by 2030 — from 7.0 in 2025 to a central estimate of 5.9 (95% range 0.00–12). A 5-year backtest shows a typical error of ±364.5%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20265.60.0012
20275.70.0012
20285.70.0012
20295.80.0012
20305.90.0012

Mallard Survey Routes in Delaware

Routes recording Mallard in Delaware.
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 →
Blackbird3520251995
Wilmington2320141979
Bethany Bch1519901969
Mt Pleasant1020191969
Dover519871966
Holleyville 2520192006
Pepperbox 2520252018
Frederica320101966
Georgetown320181994
Harrington220251973
Frankford220081992
Holleyville220041969
Lowes Xrds219911986
Milton120071975
Pepperbox120051999

Mallard Population Trend in Other States

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

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