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Species · California · BBS 2025 Release · 1966–2024

Black-necked Stilt Population Trend in California

All statesShorebirds

Black-necked Stilt in California has collapsed: down 87% on the route-weighted index since 1970.

-87%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 →
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 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 collapsed in California: down 87% 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 rise about 109% by 2029 — from 0.42 in 2024 to a central estimate of 0.88 (95% range 0.00–4.5). A 5-year backtest shows a typical error of ±536.9%, with 100% of held-out values landing inside the 95% band.

+109%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 →
0.88Projected 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 →
0.00–4.595% 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 →
±536.9%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 rise about 109% by 2029 — from 0.42 in 2024 to a central estimate of 0.88 (95% range 0.00–4.5). A 5-year backtest shows a typical error of ±536.9%, with 100% 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 →
20251.10.004.7
20261.00.004.7
20270.970.004.6
20280.920.004.6
20290.880.004.5

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
Dorris5320191972
Likely2420241985
Oilfields1219981973
Hughson820241982
Brawley820101971
Zamora820041977
Ora Loma819951972
Carrizo Pln719981970
Moreno720181984
Riovista519721972
Caruthers519851972
Oroville519981998
Tres Pinos 2520062006
Glenn420151972
Honey Lake420231974
Imperial Dam419871982
Crowder Flat320032003
Collegeville320001982
San Ysidro320041976
Cedarville320132013
Big Bear319691969
Tipton319801978
Niland320241973
Alamo River319941974

Black-necked Stilt Population Trend in Other States

alabamaarizonaarkansascoloradodelawarefloridageorgiaidahoillinoiskansaslouisianamarylandmississippimissourimontananebraskanevadanew-mexiconorth-carolinaoklahomaoregonsouth-carolinasouth-dakotatennesseetexasutahwashingtonwyoming

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