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

Western Grebe In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsWetland birds

Western Grebe in Sonoran and Mojave Deserts has surged: up 99% on the route-weighted index since 1997.

+99%Since 1997TrendPercent 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 →
5Routes 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 →
20YearsYears 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 →

Western Grebe has surged in Sonoran and Mojave Deserts: up 99% on the route-weighted index since 1997.

Western Grebe In Sonoran and Mojave Deserts Population Forecast

If the recent trend holds, Western Grebe in Sonoran and Mojave Deserts is projected to stay roughly flat through 2028, near 0.08 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±60.4%, 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 →
0.08Projected 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 →
0.00–0.1795% 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 →
±60.4%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, Western Grebe in Sonoran and Mojave Deserts is projected to stay roughly flat through 2028, near 0.08 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±60.4%, with 100% of held-out values landing inside the 95% band.19942028
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 →
20240.080.000.17
20250.080.000.17
20260.080.000.17
20270.080.000.17
20280.080.000.17

Routes In Sonoran and Mojave Deserts

Routes recording Western 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 LakeARIZONA42017
Ash MeadowsNEVADA22001
Alamo Res.ARIZONA12023
ArabyARIZONA12021
NelsonNEVADA12007

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