BirdAnalyst
Species · BCR 11 · BBS 2025 Release · 1966–2024

Hooded Merganser In Prairie Potholes

All regionsPrairie PotholesWaterfowl

Hooded Merganser in Prairie Potholes has surged: up 107% on the route-weighted index since 1973.

+107%Since 1973TrendPercent 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 →
48Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
40YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 →

Hooded Merganser has surged in Prairie Potholes: up 107% on the route-weighted index since 1973.

Hooded Merganser In Prairie Potholes Population Forecast

If the recent trend holds, Hooded Merganser in Prairie Potholes is projected to stay roughly flat through 2029, near 0.15 (95% range 0.01–0.28). A 5-year backtest shows a typical error of ±33.5%, with 80% of held-out values landing inside the 95% band.

+4%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 →
0.15Projected 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 →
0.01–0.2895% 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 →
±33.5%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, Hooded Merganser in Prairie Potholes is projected to stay roughly flat through 2029, near 0.15 (95% range 0.01–0.28). A 5-year backtest shows a typical error of ±33.5%, with 80% 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 →
20250.140.010.27
20260.140.010.27
20270.140.010.28
20280.140.010.28
20290.150.010.28

Routes In Prairie Potholes

Routes recording Hooded Merganser in Prairie Potholes.
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 StoneMINNESOTA82012
ScrantonIOWA42013
RoswellSOUTH-DAKOTA42014
ChandlerMINNESOTA32019
FormanNORTH-DAKOTA32022
CarpioNORTH-DAKOTA32003
DenbighNORTH-DAKOTA32022
KanawhaIOWA21992
GluekMINNESOTA22004
GlyndonMINNESOTA22015
OkleeMINNESOTA22004
BeltramiMINNESOTA22010
FranklinMINNESOTA22014
Lake GeorgeNORTH-DAKOTA22022
CooperstownNORTH-DAKOTA22024
Horsehead LkNORTH-DAKOTA22024
BuchananNORTH-DAKOTA22024
LakotaNORTH-DAKOTA22005
RollaNORTH-DAKOTA22022
NilesNORTH-DAKOTA22013
BraddockNORTH-DAKOTA22014
Turtle MtnsNORTH-DAKOTA22022
RaymondSOUTH-DAKOTA22007
TitonkaIOWA11993
HuntleyMINNESOTA11982

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