BirdAnalyst
Species · BCR 32 · BBS 2025 Release · 1966–2024

Golden-crowned Kinglet In Coastal California

All regionsCoastal CaliforniaForest birds

Golden-crowned Kinglet in Coastal California has surged: up 198% on the route-weighted index since 1975.

+198%Since 1975TrendPercent 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 →
13Routes 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 →
45YearsYears 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 →

Golden-crowned Kinglet has surged in Coastal California: up 198% on the route-weighted index since 1975.

Forecast

If the recent trend holds, Golden-crowned Kinglet in Coastal California is projected to rise about 336% by 2029 — from 0.17 in 2024 to a central estimate of 0.74 (95% range 0.01–1.5). A 5-year backtest shows a typical error of ±365.3%, with 20% of held-out values landing inside the 95% band.

+336%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 →
0.74Projected 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 →
0.01–1.595% 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 →
±365.3%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, Golden-crowned Kinglet in Coastal California is projected to rise about 336% by 2029 — from 0.17 in 2024 to a central estimate of 0.74 (95% range 0.01–1.5). A 5-year backtest shows a typical error of ±365.3%, with 20% of held-out values landing inside the 95% band.19702029
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 →
20250.700.001.4
20260.710.001.4
20270.720.001.4
20280.730.011.5
20290.740.011.5

Routes In Coastal California

Routes recording Golden-crowned Kinglet 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 →
Point ReyesCALIFORNIA52023
CohassetCALIFORNIA32024
FairfaxCALIFORNIA32024
FallsvaleCALIFORNIA21970
TehamaCALIFORNIA21980
Waterman GapCALIFORNIA22021
PescaderoCALIFORNIA22024
WoodlandsCALIFORNIA22022
TomheadCALIFORNIA22011
ValyermoCALIFORNIA12016
MoragaCALIFORNIA11988
Mark WestCALIFORNIA11978
Cal Hot SpgsCALIFORNIA12017

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