BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Black-necked Stilt In Coastal California

All regionsCoastal CaliforniaShorebirds

Black-necked Stilt in Coastal California has collapsed: down 98% on the route-weighted index since 1970.

-98%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 →
42Routes 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 →
55YearsYears 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 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 Coastal California: down 98% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Black-necked Stilt in Coastal California is projected to fall about 100% by 2029 — from 0.21 in 2024 to a central estimate of 0.00 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±343.3%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–3.295% 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 →
±343.3%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 Coastal California is projected to fall about 100% by 2029 — from 0.21 in 2024 to a central estimate of 0.00 (95% range 0.00–3.2). A 5-year backtest shows a typical error of ±343.3%, 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 →
20250.000.003.2
20260.000.003.2
20270.000.003.2
20280.000.003.2
20290.000.003.2

Routes In Coastal California

Routes recording Black-necked Stilt in Coastal 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 VistaCALIFORNIA842019
OilfieldsCALIFORNIA121998
HughsonCALIFORNIA82024
ZamoraCALIFORNIA82004
Ora LomaCALIFORNIA81995
MorenoCALIFORNIA72018
Carrizo PlnCALIFORNIA71998
RiovistaCALIFORNIA51972
CaruthersCALIFORNIA51985
OrovilleCALIFORNIA51998
Tres Pinos 2CALIFORNIA52006
GlennCALIFORNIA42015
CollegevilleCALIFORNIA32000
San YsidroCALIFORNIA32004
Big BearCALIFORNIA31969
Mesa GrandeCALIFORNIA32005
TiptonCALIFORNIA31980
PenningtonCALIFORNIA22024
Tres PinosCALIFORNIA22001
BakersfieldCALIFORNIA22018
Harbor LakeCALIFORNIA21985
HollisterCALIFORNIA22003
PowayCALIFORNIA21980
Cp. PendletonCALIFORNIA21993
MaricopaCALIFORNIA21990

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