BirdAnalyst
Species · BCR 11 · BBS 2026 Release · 1966–2025

Hooded Merganser In Prairie Potholes

All regionsPrairie PotholesWaterfowl

Hooded Merganser in Prairie Potholes has risen sharply: up 66% on the route-weighted index since 1973.

+66%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 →
50Routes 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 →
41YearsYears 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 risen sharply in Prairie Potholes: up 66% 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 fall about 25% by 2030 — from 0.20 in 2025 to a central estimate of 0.15 (95% range 0.02–0.29). A 5-year backtest shows a typical error of ±37.5%, with 80% of held-out values landing inside the 95% band.

-25%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 →
0.15Projected 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 →
0.02–0.2995% 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 →
±37.5%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 fall about 25% by 2030 — from 0.20 in 2025 to a central estimate of 0.15 (95% range 0.02–0.29). A 5-year backtest shows a typical error of ±37.5%, with 80% 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 →
20260.150.010.28
20270.150.010.28
20280.150.020.28
20290.150.020.28
20300.150.020.29

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
CooperstownNORTH-DAKOTA42025
RoswellSOUTH-DAKOTA42014
ChandlerMINNESOTA32019
FormanNORTH-DAKOTA32022
CarpioNORTH-DAKOTA32003
DenbighNORTH-DAKOTA32022
Sheyenne LkNORTH-DAKOTA32025
KanawhaIOWA21992
GluekMINNESOTA22004
GlyndonMINNESOTA22015
OkleeMINNESOTA22004
BeltramiMINNESOTA22010
FranklinMINNESOTA22014
Lake GeorgeNORTH-DAKOTA22022
Horsehead LkNORTH-DAKOTA22024
BuchananNORTH-DAKOTA22024
LakotaNORTH-DAKOTA22005
RollaNORTH-DAKOTA22022
NilesNORTH-DAKOTA22013
BraddockNORTH-DAKOTA22014
MontpelierNORTH-DAKOTA22025
Lakota 2NORTH-DAKOTA22025
RaymondSOUTH-DAKOTA22007

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