BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Yellow-bellied Flycatcher

TyrannidaeAerial insectivoresEmpidonax flaviventris

Yellow-bellied Flycatcher has increased: up 36% on the route-weighted index since 1968.

+36%Since 1968TrendPercent 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 →
211RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years 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 Yellow-bellied Flycatcher

The Yellow-bellied Flycatcher (Empidonax flaviventris) 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 211 Breeding Bird Survey routes across 10 states, most concentrated in the Atlantic Northern Forest.
Family
Tyrannidae · Aerial insectivores

Notable Yellow-bellied 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 →

No notable trend signals for Yellow-bellied Flycatcher. See the full index history below.

Yellow-bellied Flycatcher Population Forecast

If the recent trend holds, Yellow-bellied Flycatcher is projected to stay roughly flat through 2029, near 0.05 (95% range 0.03–0.07). A 5-year backtest shows a typical error of ±16.6%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.05Projected 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 →
0.03–0.0795% 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 →
±16.6%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, Yellow-bellied Flycatcher is projected to stay roughly flat through 2029, near 0.05 (95% range 0.03–0.07). A 5-year backtest shows a typical error of ±16.6%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.050.030.07
20260.050.030.07
20270.050.030.07
20280.050.030.07
20290.050.030.07

Where the Yellow-bellied Flycatcher Is Detected

BBS routes recording Yellow-bellied Flycatcher, sized by most recent count.

Yellow-bellied Flycatcher Population Trend by State

Yellow-bellied 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 →
Alaska15×199515
Maine-89%197257
Massachusettsinsufficient datan/a1
Michigan+52%198027
Minnesota12×197027
New Hampshire-82%196813
New York-52%197019
Pennsylvaniainsufficient datan/a2
Vermont-62%197117
Wisconsin+101%196933

Yellow-bellied Flycatcher Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Yellow-bellied 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 →
BCR 418×199614
Boreal Hardwood Transition13×196876
Atlantic Northern Forest-81%1968101
Prairie Hardwood Transition-57%197410

Yellow-bellied Flycatcher Conservation Status

Our route-weighted index shows it up about 36% since 1968. 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.