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

Common Yellowthroat In Coastal California

All regionsCoastal CaliforniaForest birds

Common Yellowthroat in Coastal California has surged: up 24× on the route-weighted index since 1970.

24×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 →
67Routes 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 →
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 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 increasecomputed 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 Yellowthroat has surged in Coastal California: up 24× on the route-weighted index since 1970.

Common Yellowthroat In Coastal California Population Forecast

If the recent trend holds, Common Yellowthroat in Coastal California is projected to fall about 29% by 2030 — from 1.8 in 2025 to a central estimate of 1.3 (95% range 0.42–2.2). A 5-year backtest shows a typical error of ±34.7%, with 100% of held-out values landing inside the 95% band.

-29%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 →
1.3Projected 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 →
0.42–2.295% 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 →
±34.7%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 Yellowthroat in Coastal California is projected to fall about 29% by 2030 — from 1.8 in 2025 to a central estimate of 1.3 (95% range 0.42–2.2). A 5-year backtest shows a typical error of ±34.7%, with 100% 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 →
20261.20.362.1
20271.20.382.1
20281.30.392.1
20291.30.412.1
20301.30.422.2

Routes In Coastal California

Routes recording Common Yellowthroat 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 →
Jofegan 2CALIFORNIA202025
Cp. PendletonCALIFORNIA152004
Ora LomaCALIFORNIA142025
Staten Is.CALIFORNIA122025
PowayCALIFORNIA71980
South LakeCALIFORNIA72006
JofeganCALIFORNIA62023
Harbor Lake 2CALIFORNIA62024
Foster ParkCALIFORNIA51994
San YsidroCALIFORNIA52019
Point ReyesCALIFORNIA52025
AthloneCALIFORNIA51979
MorenoCALIFORNIA42025
GreenfieldCALIFORNIA42025
FairfaxCALIFORNIA32024
El ToroCALIFORNIA31999
Elizabeth LkCALIFORNIA32016
GlennCALIFORNIA32022
Lake Hemet 2CALIFORNIA32018
Anza 2CALIFORNIA32024
HollisterCALIFORNIA22007
Morro BayCALIFORNIA22019
OrlandCALIFORNIA22019
S CatalinaCALIFORNIA22025
Mesa GrandeCALIFORNIA22024

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