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Species · BCR 25 · BBS 2025 Release · 1966–2024

Pied-billed Grebe In West Gulf Coastal Plain / Ouachitas

All regionsWest Gulf Coastal Plain / OuachitasWetland birds

Pied-billed Grebe in West Gulf Coastal Plain / Ouachitas has fallen sharply: down 62% on the route-weighted index since 1981.

-62%Since 1981TrendPercent 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 →
8Routes 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 →
18YearsYears 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 declinecomputed 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 fallen sharply in West Gulf Coastal Plain / Ouachitas: down 62% on the route-weighted index since 1981.

Pied-billed Grebe In West Gulf Coastal Plain / Ouachitas Population Forecast

If the recent trend holds, Pied-billed Grebe in West Gulf Coastal Plain / Ouachitas is projected to stay roughly flat through 2022, near 0.01 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±81.7%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2022TrendPercent 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 →
0.01Projected 2022 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.0795% 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 →
±81.7%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 West Gulf Coastal Plain / Ouachitas is projected to stay roughly flat through 2022, near 0.01 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±81.7%, with 80% of held-out values landing inside the 95% band.19742022
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 →
20180.010.000.07
20190.010.000.07
20200.010.000.07
20210.010.000.07
20220.010.000.07

Routes In West Gulf Coastal Plain / Ouachitas

Routes recording Pied-billed Grebe in West Gulf Coastal Plain / Ouachitas.
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 →
New WaverlyTEXAS31981
De RidderLOUISIANA22003
CheniereLOUISIANA11989
IvanLOUISIANA12006
NatchezLOUISIANA12012
Big CedarOKLAHOMA11982
GoodwaterOKLAHOMA12017
LivingstonTEXAS11974

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