BirdAnalyst
Species · BCR 33 · BBS 2025 Release · 1966–2024

Pied-billed Grebe In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsWetland birds

Pied-billed Grebe in Sonoran and Mojave Deserts has surged: up 227% on the route-weighted index since 1979.

+227%Since 1979TrendPercent 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 →
14Routes 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 →
44YearsYears 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 Sonoran and Mojave Deserts: up 227% on the route-weighted index since 1979.

Pied-billed Grebe In Sonoran and Mojave Deserts Population Forecast

If the recent trend holds, Pied-billed Grebe in Sonoran and Mojave Deserts is projected to rise about 65% by 2028 — from 0.13 in 2023 to a central estimate of 0.22 (95% range 0.00–0.67). A 5-year backtest shows a typical error of ±50.7%, with 100% of held-out values landing inside the 95% band.

+65%Change 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 →
0.22Projected 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 →
0.00–0.6795% 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 →
±50.7%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 Sonoran and Mojave Deserts is projected to rise about 65% by 2028 — from 0.13 in 2023 to a central estimate of 0.22 (95% range 0.00–0.67). A 5-year backtest shows a typical error of ±50.7%, with 100% of held-out values landing inside the 95% band.19762028
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 →
20240.210.000.66
20250.210.000.66
20260.220.000.66
20270.220.000.67
20280.220.000.67

Routes In Sonoran and Mojave Deserts

Routes recording Pied-billed Grebe in Sonoran and Mojave Deserts.
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 →
Cibola LakeARIZONA42022
Willow Beach 2ARIZONA42021
ArabyARIZONA22023
LagunaARIZONA12015
Alamo Res.ARIZONA12023
Haiwee ResCALIFORNIA12000
Palo VerdeCALIFORNIA12019
NilandCALIFORNIA12023
BlytheCALIFORNIA11976
Imperial DamCALIFORNIA12006
Lone PineCALIFORNIA11993
BrawleyCALIFORNIA11988
BeattyNEVADA11986
Ash MeadowsNEVADA12019

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