BirdAnalyst
Species · BCR 26 · BBS 2026 Release · 1966–2025

Pied-billed Grebe In Mississippi Alluvial Valley

All regionsMississippi Alluvial ValleyWetland birds

Pied-billed Grebe in Mississippi Alluvial Valley has surged: up 103% on the route-weighted index since 1975.

+103%Since 1975TrendPercent 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 →
20Routes 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 →

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 Mississippi Alluvial Valley: up 103% on the route-weighted index since 1975.

Pied-billed Grebe In Mississippi Alluvial Valley Population Forecast

If the recent trend holds, Pied-billed Grebe in Mississippi Alluvial Valley is projected to fall about 45% by 2030 — from 0.25 in 2025 to a central estimate of 0.14 (95% range 0.00–0.30). A 5-year backtest shows a typical error of ±103.9%, with 100% of held-out values landing inside the 95% band.

-45%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 →
0.14Projected 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 →
0.00–0.3095% 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 →
±103.9%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 Mississippi Alluvial Valley is projected to fall about 45% by 2030 — from 0.25 in 2025 to a central estimate of 0.14 (95% range 0.00–0.30). A 5-year backtest shows a typical error of ±103.9%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20260.130.000.29
20270.130.000.29
20280.140.000.29
20290.140.000.29
20300.140.000.30

Routes In Mississippi Alluvial Valley

Routes recording Pied-billed Grebe in Mississippi Alluvial Valley.
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 →
South BendARKANSAS52025
KeystoneLOUISIANA42008
ShawLOUISIANA42014
DelhiLOUISIANA22019
DundeeMISSISSIPPI21973
TallahatchieMISSISSIPPI22025
HughesARKANSAS11997
HarrisburgARKANSAS12000
MaynardARKANSAS12003
RamahLOUISIANA12025
Port AllenLOUISIANA12013
Tensas NwrLOUISIANA12025
AtchafalayaLOUISIANA12001
Baton RougeLOUISIANA12021
IsolaMISSISSIPPI12008
WintervilleMISSISSIPPI12009
MoonMISSISSIPPI12014
Dahomey NwrMISSISSIPPI12024
TiptonvilleTENNESSEE11977
Pawpaw 2TENNESSEE12014

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