BirdAnalyst
Guild · Vermont · BBS 2026 Release · 1966–2025

Aerial Insectivores In Vermont

All statesVermont

16 species in this guild. As a group they are -54%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1968.

Guild SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

guild collapsecomputed 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 →

Aerial insectivores as a group have fallen sharply in Vermont, down 54% since 1968.

Aerial Insectivores In Vermont Population Forecast

If the recent trend holds, Aerial insectivores in Vermont is projected to fall about 46% by 2030 — from 2.7 in 2025 to a central estimate of 1.4 (95% range 0.19–2.7). A 5-year backtest shows a typical error of ±28.4%, with 100% of held-out values landing inside the 95% band.

-46%Change by 2030TrendPercent 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 →
1.4Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.19–2.795% 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 →
±28.4%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, Aerial insectivores in Vermont is projected to fall about 46% by 2030 — from 2.7 in 2025 to a central estimate of 1.4 (95% range 0.19–2.7). A 5-year backtest shows a typical error of ±28.4%, with 100% of held-out values landing inside the 95% band.19662030
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 →
20261.80.533.0
20271.70.442.9
20281.60.362.8
20291.50.282.8
20301.40.192.7

Member Species In Vermont

Aerial insectivores species in Vermont.
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 →
Bank SwallowHirundinidae-96%
Cliff SwallowHirundinidae-86%
Chimney SwiftApodidae-76%
Olive-sided FlycatcherTyrannidae-75%
Eastern KingbirdTyrannidae-73%
Barn SwallowHirundinidae-72%
Purple MartinHirundinidae-71%
Tree SwallowHirundinidae-68%
Yellow-bellied FlycatcherTyrannidae-62%
Least FlycatcherTyrannidae-50%
Great Crested FlycatcherTyrannidae-41%
Eastern Wood-PeweeTyrannidae-25%
Eastern PhoebeTyrannidae-15%
Northern Rough-winged SwallowHirundinidae+28%
Willow FlycatcherTyrannidae+102%
Alder FlycatcherTyrannidae+233%

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.