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

Mallard Population Trend in Colorado

All statesWaterfowl

Mallard in Colorado has edged down: down 11% on the route-weighted index since 1970.

-11%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 →
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 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 11% by 2029 — from 3.0 in 2024 to a central estimate of 3.3 (95% range 0.59–6.1). A 5-year backtest shows a typical error of ±74.8%, with 100% of held-out values landing inside the 95% band.

+11%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 →
3.3Projected 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 →
0.59–6.195% 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 →
±74.8%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 11% by 2029 — from 3.0 in 2024 to a central estimate of 3.3 (95% range 0.59–6.1). A 5-year backtest shows a typical error of ±74.8%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20253.40.636.1
20263.30.626.1
20273.30.616.1
20283.30.606.1
20293.30.596.1

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 →
Mcphee Res.9020241996
Rio Grnds Rs3820241991
Dinosaur3320241995
Wildhorse L2020241988
Kiowa1220181969
Alamosa1220241988
Harmony1120241973
Boyero1020101986
Stoneham1020211993
Haswell1020221993
Arsenal 2920232016
Colona820141973
Bethune820171989
San Luis820241992
Yellowjacket Pass720241999
Cortez620081988
Thomasville620071993
Nunn620211995
Julesburg620211998
Karval620191995
Pritchett620081995
Falfa520241971
Mica Butte519871982
Willow Peak520211988
Grover520231992

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 2026-05-22.