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

Hooded Merganser Population Trend in Minnesota

All statesWaterfowl

Hooded Merganser in Minnesota has fallen sharply: down 52% on the route-weighted index since 1978.

-52%Since 1978TrendPercent 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 →
53Routes 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 →
39YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Hooded Merganser Trends in MinnesotaNotable 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 declinecomputed 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 →

Hooded Merganser has fallen sharply in Minnesota: down 52% on the route-weighted index since 1978.

Hooded Merganser Population Forecast in Minnesota

If the recent trend holds, Hooded Merganser in Minnesota is projected to rise about 74% by 2029 — from 0.07 in 2024 to a central estimate of 0.13 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±111.7%, with 100% of held-out values landing inside the 95% band.

+74%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 →
0.13Projected 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 →
0.00–0.3395% 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 →
±111.7%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, Hooded Merganser in Minnesota is projected to rise about 74% by 2029 — from 0.07 in 2024 to a central estimate of 0.13 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±111.7%, with 100% of held-out values landing inside the 95% band.19712029
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 →
20250.130.000.33
20260.130.000.33
20270.130.000.33
20280.130.000.33
20290.130.000.33

Hooded Merganser Survey Routes in Minnesota

Routes recording Hooded Merganser in Minnesota.
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 →
Big Stone820121995
Chandler320192019
Tamarac Nwr320232004
Lakeville220142011
Nebish220132013
Gluek220042004
Pine River220181999
Glyndon220152006
Oklee220042004
Beltrami220102003
Franklin220142014
Money Creek119901990
Huntley119821982
Ash Creek120132013
Sherburne Nr120211990
Minnetonka120181971
Arlington120212015
Courtland120232023
Cass Lake120162005
Princeton120181998
Osseo120172017
Knapp120241992
Appleton120122009
Cromwell120012001
Wigwam Bay119921980

Hooded Merganser Population Trend in Other States

alabamaalaskaarkansascoloradoconnecticutidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganmississippimissourimontananebraskanew-hampshirenew-yorknorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontwashingtonwest-virginiawisconsinwyoming

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