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

Generalists In Connecticut

All statesConnecticut

11 species in this guild. As a group they are -57%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 Connecticut, down 57% since 1968.

Generalists In Connecticut Population Forecast

If the recent trend holds, Generalists in Connecticut is projected to stay roughly flat through 2030, near 9.8 (95% range 3.3–16). A 5-year backtest shows a typical error of ±7.3%, with 100% of held-out values landing inside the 95% band.

-8%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 →
9.8Projected 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 →
3.3–1695% 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 →
±7.3%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 Connecticut is projected to stay roughly flat through 2030, near 9.8 (95% range 3.3–16). A 5-year backtest shows a typical error of ±7.3%, 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 →
2026114.317
2027114.117
2028103.817
2029103.617
20309.83.316

Member Species In Connecticut

Generalists species in Connecticut.
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 →
Rock PigeonColumbidae-92%
Common GrackleIcteridae-66%
European StarlingSturnidae-63%
American CrowCorvidae-38%
Brown-headed CowbirdIcteridae-33%
House SparrowPasseridae-30%
Mourning DoveColumbidae+42%
Northern MockingbirdMimidae+285%
House FinchFringillidae+599%
Common RavenCorvidae+748%
Fish CrowCorvidae13×

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