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

Pied-billed Grebe In Prairie Potholes

All regionsPrairie PotholesWetland birds

Pied-billed Grebe in Prairie Potholes has surged: up 141% on the route-weighted index since 1969.

+141%Since 1969TrendPercent 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 →
97Routes 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 →
57YearsYears 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 →

Pied-billed Grebe has surged in Prairie Potholes: up 141% on the route-weighted index since 1969.

Pied-billed Grebe In Prairie Potholes Population Forecast

If the recent trend holds, Pied-billed Grebe in Prairie Potholes is projected to rise about 32% by 2029 — from 1.6 in 2024 to a central estimate of 2.1 (95% range 0.35–3.8). A 5-year backtest shows a typical error of ±31.9%, with 100% of held-out values landing inside the 95% band.

+32%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 →
2.1Projected 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 →
0.35–3.895% 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 →
±31.9%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, Pied-billed Grebe in Prairie Potholes is projected to rise about 32% by 2029 — from 1.6 in 2024 to a central estimate of 2.1 (95% range 0.35–3.8). A 5-year backtest shows a typical error of ±31.9%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20252.00.283.7
20262.00.303.8
20272.00.323.8
20282.10.333.8
20292.10.353.8

Routes In Prairie Potholes

Routes recording Pied-billed Grebe 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 →
GeddesSOUTH-DAKOTA431999
BuchananNORTH-DAKOTA262024
White LakeSOUTH-DAKOTA152011
RoswellSOUTH-DAKOTA152012
Horsehead LkNORTH-DAKOTA132024
GettysburgSOUTH-DAKOTA132023
Danzig 2NORTH-DAKOTA102024
LakotaNORTH-DAKOTA92009
FormanNORTH-DAKOTA82024
WimbledonNORTH-DAKOTA82024
Big StoneMINNESOTA62012
Wild RoseNORTH-DAKOTA62024
CourtlandMINNESOTA52024
BroadlandSOUTH-DAKOTA52012
BrittonSOUTH-DAKOTA52022
ChokioMINNESOTA42024
WilmotSOUTH-DAKOTA42024
MaynardMINNESOTA32006
TracyMINNESOTA32018
Lake GeorgeNORTH-DAKOTA32019
DanzigNORTH-DAKOTA32013
WebsterNORTH-DAKOTA32023
NilesNORTH-DAKOTA32024
CarpioNORTH-DAKOTA32014
DenbighNORTH-DAKOTA32024

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