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

Bufflehead In Prairie Potholes

All regionsPrairie PotholesWaterfowl

Bufflehead in Prairie Potholes has surged: up 966% on the route-weighted index since 1985.

+966%Since 1985TrendPercent 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 →
15Routes 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 →
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 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 →

Bufflehead has surged in Prairie Potholes: up 966% on the route-weighted index since 1985.

Bufflehead In Prairie Potholes Population Forecast

If the recent trend holds, Bufflehead in Prairie Potholes is projected to fall about 33% by 2030 — from 0.78 in 2025 to a central estimate of 0.53 (95% range 0.08–0.98). A 5-year backtest shows a typical error of ±57.5%, with 40% of held-out values landing inside the 95% band.

-33%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 →
0.53Projected 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 →
0.08–0.9895% 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 →
±57.5%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, Bufflehead in Prairie Potholes is projected to fall about 33% by 2030 — from 0.78 in 2025 to a central estimate of 0.53 (95% range 0.08–0.98). A 5-year backtest shows a typical error of ±57.5%, with 40% of held-out values landing inside the 95% band.19802030
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 →
20260.490.040.94
20270.500.050.95
20280.510.060.96
20290.520.070.97
20300.530.080.98

Routes In Prairie Potholes

Routes recording Bufflehead 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 →
Horsehead LkNORTH-DAKOTA502025
Lake GeorgeNORTH-DAKOTA112023
Wild RoseNORTH-DAKOTA62024
VirgelleMONTANA52023
WestbyMONTANA32019
DanzigNORTH-DAKOTA32010
Sheyenne LkNORTH-DAKOTA32025
Turtle MtnsNORTH-DAKOTA32025
SunburstMONTANA21996
CooperstownNORTH-DAKOTA22025
RollaNORTH-DAKOTA22024
Douglas CrkNORTH-DAKOTA22024
BraddockNORTH-DAKOTA12021
RoswellSOUTH-DAKOTA11998
BrittonSOUTH-DAKOTA12017

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