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

Generalists In Vermont

All statesVermont

10 species in this guild. As a group they are -55%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 →

Generalists as a group have fallen sharply in Vermont, down 55% since 1968.

Generalists In Vermont Population Forecast

If the recent trend holds, Generalists in Vermont is projected to fall about 28% by 2030 — from 8.2 in 2025 to a central estimate of 6.0 (95% range 2.7–9.2). A 5-year backtest shows a typical error of ±10.9%, with 100% of held-out values landing inside the 95% band.

-28%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 →
6.0Projected 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 →
2.7–9.295% 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 →
±10.9%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, Generalists in Vermont is projected to fall about 28% by 2030 — from 8.2 in 2025 to a central estimate of 6.0 (95% range 2.7–9.2). A 5-year backtest shows a typical error of ±10.9%, 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 →
20266.83.610
20276.63.49.8
20286.43.19.6
20296.22.99.4
20306.02.79.2

Member Species In Vermont

Generalists 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 →
House SparrowPasseridae-79%
European StarlingSturnidae-76%
Brown-headed CowbirdIcteridae-73%
Common GrackleIcteridae-58%
Northern MockingbirdMimidae-40%
American CrowCorvidae-7%
Rock PigeonColumbidae+12%
House FinchFringillidae+130%
Mourning DoveColumbidae+387%
Common RavenCorvidae26×

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