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

California Gnatcatcher In Coastal California

All regionsCoastal CaliforniaForest birds

California Gnatcatcher in Coastal California has surged: up 88% on the route-weighted index since 1974.

+88%Since 1974TrendPercent 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 →
8Routes 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 →
20YearsYears 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 California Gnatcatcher in Coastal California. See the full index history below.

California Gnatcatcher In Coastal California Population Forecast

If the recent trend holds, California Gnatcatcher in Coastal California is projected to fall about 41% by 2029 — from 0.11 in 2024 to a central estimate of 0.06 (95% range 0.02–0.11). A 5-year backtest shows a typical error of ±57.2%, with 80% of held-out values landing inside the 95% band.

-41%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 →
0.06Projected 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 →
0.02–0.1195% 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 →
±57.2%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, California Gnatcatcher in Coastal California is projected to fall about 41% by 2029 — from 0.11 in 2024 to a central estimate of 0.06 (95% range 0.02–0.11). A 5-year backtest shows a typical error of ±57.2%, with 80% of held-out values landing inside the 95% band.19712029
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 →
20250.060.020.10
20260.060.020.11
20270.060.020.11
20280.060.020.11
20290.060.020.11

Routes In Coastal California

Routes recording California Gnatcatcher 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 →
Oak GroveCALIFORNIA22017
Elsinore MtnCALIFORNIA21971
Harbor Lake 2CALIFORNIA22024
Jofegan 2CALIFORNIA22024
MorenoCALIFORNIA12024
San YsidroCALIFORNIA11988
Cp. PendletonCALIFORNIA12003
AnzaCALIFORNIA11976

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