BirdAnalyst
Species · California · BBS 2025 Release · 1966–2024

Wrentit Population Trend in California

All statesGeneralists

Wrentit in California has edged down: down 22% on the route-weighted index since 1970.

-22%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 →
154Routes 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 Wrentit 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 →

No notable trend signals for Wrentit in California. See the full index history below.

Wrentit Population Forecast in California

If the recent trend holds, Wrentit in California is projected to fall about 11% by 2029 — from 6.2 in 2024 to a central estimate of 5.5 (95% range 3.6–7.4). A 5-year backtest shows a typical error of ±17.4%, with 100% of held-out values landing inside the 95% band.

-11%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 →
5.5Projected 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 →
3.6–7.495% 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 →
±17.4%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, Wrentit in California is projected to fall about 11% by 2029 — from 6.2 in 2024 to a central estimate of 5.5 (95% range 3.6–7.4). A 5-year backtest shows a typical error of ±17.4%, 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 →
20255.63.77.5
20265.63.77.4
20275.63.77.4
20285.53.77.4
20295.53.67.4

Wrentit Survey Routes in California

Routes recording Wrentit 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 →
Elsinore Mtn12420241970
Rumsey7920081969
Lake Cachuma7620161972
Mt Baldy7420241970
Hough Springs6320071999
Cuyamaca Pk6120241970
San Benito Mtn.5820092003
Stonyford4420182015
Jofegan 24020242024
Poway4019801973
Tujunga3520211970
Forest Hill3420221997
Silver City3320131972
Tomhead3220111998
Folsom3120241984
Greenfield3120241973
Coulterville3020191997
Bartlett Sps2920181972
Big Flat2920142002
Foster Park2719941968
Lake Berryessa2620242023
Alamar2420171997
French Gulch2220112002
Fish Rock2120141968
Jofegan2120232006

Wrentit Population Trend in Other States

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