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Species · Utah · BBS 2025 Release · 1966–2024

Pied-billed Grebe Population Trend in Utah

All statesWetland birds

Pied-billed Grebe in Utah has collapsed: down 80% on the route-weighted index since 1981.

-80%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 →
20Routes In StateSurvey 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 Pied-billed Grebe Trends in UtahNotable 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 collapsed in Utah: down 80% on the route-weighted index since 1981.

Pied-billed Grebe Population Forecast in Utah

If the recent trend holds, Pied-billed Grebe in Utah is projected to stay roughly flat through 2028, near 0.03 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±71.7%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028TrendPercent 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 →
0.03Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.3395% 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 →
±71.7%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 Utah is projected to stay roughly flat through 2028, near 0.03 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±71.7%, with 100% of held-out values landing inside the 95% band.19742028
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 →
20240.040.000.35
20250.040.000.34
20260.040.000.34
20270.030.000.33
20280.030.000.33

Pied-billed Grebe Survey Routes in Utah

Routes recording Pied-billed Grebe in Utah.
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 →
M Warner Res620182018
Saleratus Cr320161995
Goshen220062000
Lynn220131995
Randolph220211993
Dixie Nf220141994
Main Canyon220171998
Promontory120221974
Neponset Res120122000
Oak City120061980
La Sal 2120042004
Boulder120162012
Bear River120232003
Callao120191992
Leamington120142014
Castle Dale120112011
Vernal120122012
Newcastle120171997
Alton120001998
Monticello120232007

Pied-billed Grebe Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasvermontvirginiawashingtonwisconsinwyoming

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