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

Willow Flycatcher In Coastal California

All regionsCoastal CaliforniaAerial insectivores

Willow Flycatcher in Coastal California has edged up: up 11% on the route-weighted index since 1972.

+11%Since 1972TrendPercent 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 →
29Routes 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 →
32YearsYears 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 Willow Flycatcher in Coastal California. See the full index history below.

Forecast

If the recent trend holds, Willow Flycatcher in Coastal California is projected to stay roughly flat through 2024, near 0.06 (95% range 0.01–0.12). A 5-year backtest shows a typical error of ±71%, with 80% of held-out values landing inside the 95% band.

n/aChange by 2024TrendPercent 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 2024 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.01–0.1295% 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 →
±71%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, Willow Flycatcher in Coastal California is projected to stay roughly flat through 2024, near 0.06 (95% range 0.01–0.12). A 5-year backtest shows a typical error of ±71%, with 80% of held-out values landing inside the 95% band.19692024
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 →
20200.060.000.12
20210.060.000.12
20220.060.000.12
20230.060.000.12
20240.060.010.12

Routes In Coastal California

Routes recording Willow Flycatcher 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 →
CoalingaCALIFORNIA71995
RiovistaCALIFORNIA21976
MorenoCALIFORNIA22019
Mt BaldyCALIFORNIA22016
GlennCALIFORNIA22005
AthloneCALIFORNIA22004
Red BluffCALIFORNIA11989
CalpellaCALIFORNIA11986
HughsonCALIFORNIA11990
Foster ParkCALIFORNIA11969
Orange CoveCALIFORNIA12002
Morro BayCALIFORNIA11977
CohassetCALIFORNIA12012
OrlandCALIFORNIA12006
FolsomCALIFORNIA12009
TujungaCALIFORNIA11972
Mesa GrandeCALIFORNIA11999
ValyermoCALIFORNIA11981
FallsvaleCALIFORNIA11975
Lockwood ValCALIFORNIA12016
Cuyamaca PkCALIFORNIA11971
SangerCALIFORNIA12013
Green ValleyCALIFORNIA11998
JacumbaCALIFORNIA11974
Gold HillCALIFORNIA11996

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