BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Dusky Flycatcher

TyrannidaeAerial insectivoresEmpidonax oberholseri

Dusky Flycatcher has surged: up 692% on the route-weighted index since 1970.

+692%Since 1970TrendPercent 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 →
598RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Dusky Flycatcher

The Dusky Flycatcher (Empidonax oberholseri) is a North American member of the Tyrant Flycatchers (Tyrannidae). In this analysis it is grouped with the aerial insectivores.

Size
4.5–9 in long (12–23 cm) — a small to medium flycatcher (typical for the family)
Habitat
Open airspace over fields, water and towns; nests in cavities, earthen banks or on structures.
Diet
Flying insects caught on the wing.
Range
Recorded on 598 Breeding Bird Survey routes across 13 states, most concentrated in the Northern Rockies.
Family
Tyrannidae · Aerial insectivores

Notable Dusky Flycatcher TrendsNotable 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 surveyed states: up 692% on the route-weighted index since 1970.

Dusky Flycatcher Population Forecast

If the recent trend holds, Dusky Flycatcher is projected to rise about 20% by 2029 — from 0.63 in 2024 to a central estimate of 0.76 (95% range 0.55–0.97). A 5-year backtest shows a typical error of ±40.1%, with 20% of held-out values landing inside the 95% band.

+20%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 →
0.76Projected 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 →
0.55–0.9795% 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 →
±40.1%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 is projected to rise about 20% by 2029 — from 0.63 in 2024 to a central estimate of 0.76 (95% range 0.55–0.97). A 5-year backtest shows a typical error of ±40.1%, with 20% of held-out values landing inside the 95% band.19682029
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 →
20250.720.510.93
20260.730.520.94
20270.740.530.95
20280.750.540.96
20290.760.550.97

Where the Dusky Flycatcher Is Detected

BBS routes recording Dusky Flycatcher, sized by most recent count.

Dusky Flycatcher Population Trend by State

Dusky Flycatcher population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Arizona+138%199011
California+245%1971109
Colorado+557%197085
Idaho+62%197346
Montana+538%197064
Nebraskainsufficient datan/a1
Nevada+171%199116
New Mexico-63%197821
Oregon+35%197085
South Dakota-34%199313
Utah+139%197953
Washington+216%197044
Wyoming+476%197050

Dusky Flycatcher Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Dusky Flycatcher population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Pacific Rainforest-40%197055
Great Basin+102%1970120
Northern Rockies+180%1970165
Sierra Nevada+32%197137
Southern Rockies / Colorado Plateau12×1970145
Badlands and Prairies17×197829
Coastal California-1%197128
Sierra Madre Occidental+46%19959

Dusky Flycatcher Conservation Status

Our route-weighted index shows it up about 692% since 1970. Aerial insectivores have fallen sharply across the continent, a decline widely linked to dwindling insect prey.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.