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Species · California · BBS 2025 Release · 1966–2024

Dusky Flycatcher Population Trend in California

All statesAerial insectivores

Dusky Flycatcher in California has surged: up 245% on the route-weighted index since 1971.

+245%Since 1971TrendPercent 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 →
109Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Dusky 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 →

Dusky Flycatcher has surged in California: up 245% on the route-weighted index since 1971.

Dusky Flycatcher Population Forecast in California

If the recent trend holds, Dusky Flycatcher in California is projected to rise about 147% by 2029 — from 1.1 in 2024 to a central estimate of 2.6 (95% range 1.4–3.8). A 5-year backtest shows a typical error of ±142.8%, with 0% of held-out values landing inside the 95% band.

+147%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 →
2.6Projected 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 →
1.4–3.895% 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 →
±142.8%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, Dusky Flycatcher in California is projected to rise about 147% by 2029 — from 1.1 in 2024 to a central estimate of 2.6 (95% range 1.4–3.8). A 5-year backtest shows a typical error of ±142.8%, with 0% of held-out values landing inside the 95% band.19692029
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 →
20252.51.33.7
20262.51.33.7
20272.61.43.7
20282.61.43.8
20292.61.43.8

Dusky Flycatcher Survey Routes in California

Routes recording Dusky 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 →
Hackamore3720102000
Crestview3020241997
Pine Mountain2220171998
Goumaz2020111997
Pilot Creek1919961994
Tahoe Nf1719941987
Dirigio1720141999
Macdoel1520191972
South Fork Mtn1520222000
Valyermo1420191971
Hat Creek1320181973
Johnsville1220241975
Greenhorn Mt1220081971
Yolla Bolly1119731973
Eagle Lake1020241969
Dardanelle1020191986
Mccloud1020211978
Lassen Park719891981
Lumberyard720241982
Bartle720211972
Little Truckee720231997
Pollock Pines720241997
Strawberry720191999
Carrville619701970
French Gulch620102002

Dusky Flycatcher Population Trend in Other States

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