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

Common Poorwill Population Trend in California

All statesAerial insectivores

Common Poorwill in California has fallen sharply: down 67% on the route-weighted index since 1970.

-67%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 →
71Routes 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 Common Poorwill 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 →

Common Poorwill has fallen sharply in California: down 67% on the route-weighted index since 1970.

Common Poorwill Population Forecast in California

If the recent trend holds, Common Poorwill in California is projected to fall about 15% by 2030 — from 0.06 in 2025 to a central estimate of 0.05 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±53.1%, with 80% of held-out values landing inside the 95% band.

-15%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 →
0.05Projected 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 →
0.00–0.1395% 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 →
±53.1%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, Common Poorwill in California is projected to fall about 15% by 2030 — from 0.06 in 2025 to a central estimate of 0.05 (95% range 0.00–0.13). A 5-year backtest shows a typical error of ±53.1%, with 80% 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 →
20260.050.000.14
20270.050.000.14
20280.050.000.14
20290.050.000.14
20300.050.000.13

Common Poorwill Survey Routes in California

Routes recording Common Poorwill 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 →
Onyx519981968
Mt Baldy320241972
Big Bear319831969
Elizabeth Lk219741974
Ventucopa220021975
Hullville219941970
Westville220181997
Mt Pinos 2220212005
Crowley Lake219831978
Goldstone219921992
Barstow219871968
Oak Grove220251975
Clear Lk Res220002000
Hough Springs220072002
Bartlett Sps220181974
Eureka Val219951990
Cleveland Nf 2220222019
Cima219951983
Lockwood Val220121972
Horse Creek120032003
Nubieber120181978
Green Valley120182015
Lake Cachuma119821976
Eagle Lake120112006
Jacumba119941986

Common Poorwill Population Trend in Other States

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