BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Pied-billed Grebe In Great Basin

All regionsGreat BasinWetland birds

Pied-billed Grebe in Great Basin has held roughly steady: down 5% on the route-weighted index since 1970.

-5%Since 1970TrendPercent 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 →
87Routes 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 →
56YearsYears 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 Pied-billed Grebe in Great Basin. See the full index history below.

Pied-billed Grebe In Great Basin Population Forecast

If the recent trend holds, Pied-billed Grebe in Great Basin is projected to rise about 167% by 2029 — from 0.09 in 2024 to a central estimate of 0.25 (95% range 0.03–0.47). A 5-year backtest shows a typical error of ±180.7%, with 80% of held-out values landing inside the 95% band.

+167%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 →
0.25Projected 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 →
0.03–0.4795% 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 →
±180.7%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 Great Basin is projected to rise about 167% by 2029 — from 0.09 in 2024 to a central estimate of 0.25 (95% range 0.03–0.47). A 5-year backtest shows a typical error of ±180.7%, with 80% 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 →
20250.250.030.47
20260.250.030.47
20270.250.030.47
20280.250.030.47
20290.250.030.47

Routes In Great Basin

Routes recording Pied-billed Grebe in Great Basin.
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 →
Crowder FlatCALIFORNIA122018
BrewsterWASHINGTON62018
IngallsCALIFORNIA51994
DorrisCALIFORNIA52019
Barnes ValOREGON51987
Catlow RimOREGON42024
EwanWASHINGTON42019
OthelloWASHINGTON41991
Lone RockOREGON32015
Warner VallyOREGON32024
Iron GateCALIFORNIA22019
TriangleIDAHO22021
Blackft ResIDAHO21998
Cedar HillIDAHO22016
Daniels ResIDAHO22000
CortezNEVADA22023
Dobbin CreekNEVADA22018
Blizzard GapOREGON22023
MerrillOREGON22013
GoshenUTAH22006
LynnUTAH22013
WapatoWASHINGTON21994
TonasketWASHINGTON22016
KeystoneWASHINGTON22015
Moses CouleeWASHINGTON22023

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