BirdAnalyst
Species · BCR 32 · BBS 2026 Release · 1966–2025

Bewick's Wren In Coastal California

All regionsCoastal CaliforniaForest birds

Bewick's Wren in Coastal California has increased: up 33% on the route-weighted index since 1970.

+33%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 →
115Routes 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 →
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 SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Bewick's Wren in Coastal California. See the full index history below.

Bewick's Wren In Coastal California Population Forecast

If the recent trend holds, Bewick's Wren in Coastal California is projected to rise about 13% by 2030 — from 8.2 in 2025 to a central estimate of 9.2 (95% range 5.8–13). A 5-year backtest shows a typical error of ±32.6%, with 80% of held-out values landing inside the 95% band.

+13%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 →
9.2Projected 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 →
5.8–1395% 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 →
±32.6%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, Bewick's Wren in Coastal California is projected to rise about 13% by 2030 — from 8.2 in 2025 to a central estimate of 9.2 (95% range 5.8–13). A 5-year backtest shows a typical error of ±32.6%, 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 →
20269.15.712
20279.15.812
20289.15.812
20299.25.813
20309.25.813

Routes In Coastal California

Routes recording Bewick's Wren 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 →
Santa Cruz ICALIFORNIA771988
PowayCALIFORNIA591980
S CatalinaCALIFORNIA502025
South LakeCALIFORNIA352006
AuburnCALIFORNIA331980
Cuyamaca PkCALIFORNIA312025
StonyfordCALIFORNIA282018
Waterman GapCALIFORNIA272025
Tres Pinos 2CALIFORNIA272011
Mt BaldyCALIFORNIA212024
Hough SpringsCALIFORNIA212007
Tres PinosCALIFORNIA192003
ColmaCALIFORNIA181972
RumseyCALIFORNIA162008
Point ReyesCALIFORNIA162025
JacumbaCALIFORNIA162025
Lake BerryessaCALIFORNIA152025
Lake CachumaCALIFORNIA152016
TomheadCALIFORNIA152011
Lockwood ValCALIFORNIA142019
Elsinore MtnCALIFORNIA142025
CoyoteCALIFORNIA142025
Elizabeth LkCALIFORNIA132016
GreenfieldCALIFORNIA132025
Bartlett SpsCALIFORNIA122018

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