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

Mallard Population Trend in Colorado

All statesWaterfowl

Mallard in Colorado has edged down: down 15% on the route-weighted index since 1970.

-15%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 →
151Routes 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 →
57YearsYears 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 ColoradoNotable 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 Colorado. See the full index history below.

Mallard Population Forecast in Colorado

If the recent trend holds, Mallard in Colorado is projected to rise about 60% by 2030 — from 2.0 in 2025 to a central estimate of 3.2 (95% range 0.48–5.9). A 5-year backtest shows a typical error of ±83%, with 100% of held-out values landing inside the 95% band.

+60%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 →
3.2Projected 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 →
0.48–5.995% 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 →
±83%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 Colorado is projected to rise about 60% by 2030 — from 2.0 in 2025 to a central estimate of 3.2 (95% range 0.48–5.9). A 5-year backtest shows a typical error of ±83%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20263.30.536.0
20273.20.526.0
20283.20.516.0
20293.20.495.9
20303.20.485.9

Mallard Survey Routes in Colorado

Routes recording Mallard in Colorado.
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 →
Rio Grnds Rs3820241991
Mcphee Res.3520251996
Wildhorse L2020251988
Piedra2020251993
Mesaverde Np1720251997
Tarryall1420251988
Alamosa1320251988
Kiowa1220181969
Boyero1020101986
Stoneham1020211993
Haswell1020221993
Walden920251990
Colona820141973
Bethune820171989
Blackhead Pk820251992
Yellowjacket Pass820251999
Cortez620081988
Thomasville620071993
Tincup620251992
Nunn620211995
Julesburg620211998
Karval620191995
Pritchett620081995
Buford520251970
Mica Butte519871982

Mallard Population Trend in Other States

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

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