BirdAnalyst
Species · California · BBS 2026 Release · 1966–2025

Black-necked Stilt Population Trend in California

All statesShorebirds

Black-necked Stilt in California has fallen sharply: down 74% on the route-weighted index since 1970.

-74%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 →
62Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Black-necked Stilt Trends in CaliforniaNotable 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 →

Black-necked Stilt has fallen sharply in California: down 74% on the route-weighted index since 1970.

Black-necked Stilt Population Forecast in California

If the recent trend holds, Black-necked Stilt in California is projected to fall about 29% by 2030 — from 1.2 in 2025 to a central estimate of 0.84 (95% range 0.00–4.5). A 5-year backtest shows a typical error of ±521.2%, with 100% of held-out values landing inside the 95% band.

-29%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 →
0.84Projected 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 →
0.00–4.595% 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 →
±521.2%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, Black-necked Stilt in California is projected to fall about 29% by 2030 — from 1.2 in 2025 to a central estimate of 0.84 (95% range 0.00–4.5). A 5-year backtest shows a typical error of ±521.2%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20261.00.004.6
20270.980.004.6
20280.930.004.6
20290.890.004.5
20300.840.004.5

Black-necked Stilt Survey Routes in California

Routes recording Black-necked Stilt in California.
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 →
Buena Vista8420191991
Likely5720251985
Dorris5320191972
Oroville2120251998
Oilfields1219981973
Westley920251972
Hughson820241982
Brawley820101971
Zamora820041977
Ora Loma819951972
Niland820251973
Carrizo Pln719981970
Moreno720181984
Riovista519721972
Caruthers519851972
Tres Pinos 2520062006
Glenn420151972
Honey Lake420251974
Imperial Dam419871982
Crowder Flat320032003
Collegeville320001982
San Ysidro320041976
Cedarville320132013
Big Bear319691969
Tipton319801978

Black-necked Stilt Population Trend in Other States

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