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

Olive-sided Flycatcher Population Trend in Vermont

All statesAerial insectivores

Olive-sided Flycatcher in Vermont has fallen sharply: down 75% on the route-weighted index since 1969.

-75%Since 1969TrendPercent 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 →
20Routes 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 →
48YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Olive-sided 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 →

Olive-sided Flycatcher has fallen sharply in Vermont: down 75% on the route-weighted index since 1969.

Olive-sided Flycatcher Population Forecast in Vermont

If the recent trend holds, Olive-sided Flycatcher in Vermont is projected to fall about 100% by 2029 — from 0.17 in 2024 to a central estimate of 0.00 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±78.4%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.2295% 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 →
±78.4%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, Olive-sided Flycatcher in Vermont is projected to fall about 100% by 2029 — from 0.17 in 2024 to a central estimate of 0.00 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±78.4%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.010.000.23
20260.010.000.23
20270.000.000.22
20280.000.000.22
20290.000.000.22

Olive-sided Flycatcher Survey Routes in Vermont

Routes recording Olive-sided 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 →
Waterville319791979
Hardwick220161968
Marlboro119951976
North Pownal119691969
Stratton119901968
Landgrove120241967
S Reading119791968
Post Mills119761975
Shaftsbury119771976
W Rutland119771977
St Johnsbury120101970
East Haven119991967
Northfld Fls120211986
Middlesex120181969
East Calais120241968
Newbury119891987
Greensboro120041967
Hinesburg119821982
Newbury 2120122012
Stowe120241992

Olive-sided Flycatcher Population Trend in Other States

alaskaarizonacaliforniacoloradoidahomainemarylandmassachusettsmichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorknorth-carolinaohiooregonpennsylvaniasouth-dakotautahwashingtonwest-virginiawisconsinwyoming

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