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

Horned Grebe In Prairie Potholes

All regionsPrairie PotholesWetland birds

Horned Grebe in Prairie Potholes has declined: down 48% on the route-weighted index since 1971.

-48%Since 1971TrendPercent 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 →
24Routes 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 →
38YearsYears 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 →

No notable trend signals for Horned Grebe in Prairie Potholes. See the full index history below.

Forecast

If the recent trend holds, Horned Grebe in Prairie Potholes is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±50.1%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.04Projected 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 →
0.00–0.1395% 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 →
±50.1%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, Horned Grebe in Prairie Potholes is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±50.1%, with 100% 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 →
20250.040.000.13
20260.040.000.13
20270.040.000.13
20280.040.000.13
20290.040.000.13

Routes In Prairie Potholes

Routes recording Horned 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 →
Long LakeSOUTH-DAKOTA42019
WebsterNORTH-DAKOTA31997
ShelbyMONTANA22018
CooperstownNORTH-DAKOTA21996
Horsehead LkNORTH-DAKOTA22010
BuchananNORTH-DAKOTA22022
BowesmontNORTH-DAKOTA21968
RollaNORTH-DAKOTA22003
Powers LakeNORTH-DAKOTA22006
Douglas CrkNORTH-DAKOTA22013
Turtle MtnsNORTH-DAKOTA22024
Lakota 2NORTH-DAKOTA22015
BrittonSOUTH-DAKOTA22018
WylieMINNESOTA11983
DanzigNORTH-DAKOTA11995
LakotaNORTH-DAKOTA11998
NilesNORTH-DAKOTA12013
ReganNORTH-DAKOTA11980
CarpioNORTH-DAKOTA12010
LoraineNORTH-DAKOTA11995
Wild RoseNORTH-DAKOTA12019
ParshallNORTH-DAKOTA11986
Sheyenne LkNORTH-DAKOTA12009
VeblenSOUTH-DAKOTA11978

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