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Species · California · BBS 2026 Release · 1966–2025

Gray Flycatcher Population Trend in California

All statesAerial insectivores

Gray Flycatcher in California has surged: up 16× on the route-weighted index since 1973.

16×Since 1973TrendPercent 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 →
41Routes 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 →
54YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Gray Flycatcher 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 →

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 →

Gray Flycatcher has surged in California: up 16× on the route-weighted index since 1973.

Gray Flycatcher Population Forecast in California

If the recent trend holds, Gray Flycatcher in California is projected to stay roughly flat through 2030, near 1.2 (95% range 0.75–1.6). A 5-year backtest shows a typical error of ±54.8%, with 40% of held-out values landing inside the 95% band.

+8%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 →
1.2Projected 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 →
0.75–1.695% 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 →
±54.8%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, Gray Flycatcher in California is projected to stay roughly flat through 2030, near 1.2 (95% range 0.75–1.6). A 5-year backtest shows a typical error of ±54.8%, with 40% of held-out values landing inside the 95% band.19712030
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 →
20261.10.671.5
20271.10.691.5
20281.10.711.6
20291.20.731.6
20301.20.751.6

Gray Flycatcher Survey Routes in California

Routes recording Gray Flycatcher 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 →
Navarro5319931993
Crowder Flat4220192002
Eagle Lake1920251978
Tionesta1920212005
Crowley Lake1620251979
Ingalls1620251973
Clear Lk Res1520181973
Madeline1120252010
Little Truckee1020251997
Chilcoot1020241998
Pine Mountain820062006
Ravendale820251975
Goumaz720111999
Last Chance520191994
Davis Creek420251983
Crestview420251997
Deep Springs320221972
Green Valley219881977
Gazelle220172000
San Benito Mtn.220082008
Big Pine220251971
Medicine Mtn.220102010
Mt Shasta219951988
Chaos Crater219941994
Bartle220211977

Gray Flycatcher Population Trend in Other States

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