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Species · California · BBS 2025 Release · 1966–2024

Long-billed Curlew Population Trend in California

All statesShorebirds

Long-billed Curlew in California has collapsed: down 95% on the route-weighted index since 1972.

-95%Since 1972TrendPercent 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 →
22Routes 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 →
53YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Long-billed Curlew 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 →

Long-billed Curlew has collapsed in California: down 95% on the route-weighted index since 1972.

Long-billed Curlew Population Forecast in California

If the recent trend holds, Long-billed Curlew in California is projected to stay roughly flat through 2028, near 0.10 (95% range 0.00–0.46). A 5-year backtest shows a typical error of ±540.3%, 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 →
0.10Projected 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 →
0.00–0.4695% 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 →
±540.3%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, Long-billed Curlew in California is projected to stay roughly flat through 2028, near 0.10 (95% range 0.00–0.46). A 5-year backtest shows a typical error of ±540.3%, with 100% of held-out values landing inside the 95% band.19702028
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 →
20240.110.000.46
20250.110.000.46
20260.110.000.46
20270.100.000.46
20280.100.000.46

Long-billed Curlew Survey Routes in California

Routes recording Long-billed Curlew 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 →
Athlone2219721972
Atwater1220071971
Cedarville820191974
Riovista519711971
Ora Loma419761976
Honey Lake320191972
Glenn220051991
Caruthers219841984
Dorris220191972
Nubieber120181980
Likely120181971
Madeline120212014
Crowley Lake120222013
Westley119921992
Haiwee Res119981998
Parkfield119701970
Davis Creek120231972
Macdoel119931993
Tranquillity120001984
Yreka120092009
Ingalls119951995
Ravendale120001976

Long-billed Curlew Population Trend in Other States

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