BirdAnalyst
Species · Vermont · BBS 2025 Release · 1966–2024

Yellow-bellied Flycatcher Population Trend in Vermont

All statesAerial insectivores

Yellow-bellied Flycatcher in Vermont has fallen sharply: down 62% on the route-weighted index since 1971.

-62%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 →
17Routes 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 →
22YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Yellow-bellied Flycatcher Trends in VermontNotable 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 declinecomputed 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 →

Yellow-bellied Flycatcher has fallen sharply in Vermont: down 62% on the route-weighted index since 1971.

Yellow-bellied Flycatcher Population Forecast in Vermont

If the recent trend holds, Yellow-bellied Flycatcher in Vermont is projected to fall about 59% by 2024 — from 0.06 in 2019 to a central estimate of 0.02 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±149.7%, with 100% of held-out values landing inside the 95% band.

-59%Change 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 →
0.02Projected 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 →
0.00–0.2195% 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 →
±149.7%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 in Vermont is projected to fall about 59% by 2024 — from 0.06 in 2019 to a central estimate of 0.02 (95% range 0.00–0.21). A 5-year backtest shows a typical error of ±149.7%, with 100% of held-out values landing inside the 95% band.19682024
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 →
20200.040.000.22
20210.030.000.22
20220.030.000.21
20230.030.000.21
20240.020.000.21

Yellow-bellied Flycatcher Survey Routes in Vermont

Routes recording Yellow-bellied Flycatcher in Vermont.
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 →
East Haven220141980
Marlboro119751975
Stratton119711971
Landgrove120192019
S Reading119791972
Post Mills119781975
Shaftsbury119721972
St Johnsbury120011970
Northfld Fls120072001
Middlesex119901970
East Calais119821980
Hardwick120041978
Greensboro119891968
Fletcher119851985
Waterville119791979
Hinesburg119881988
Stowe119901990

Yellow-bellied Flycatcher Population Trend in Other States

alaskamainemassachusettsmichiganminnesotanew-hampshirenew-yorkpennsylvaniawisconsin

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