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

Generalists In Tennessee

All statesTennessee

12 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 →

Generalists as a group have fallen sharply in Tennessee, down 54% since 1968.

Generalists In Tennessee Population Forecast

If the recent trend holds, Generalists in Tennessee is projected to fall about 46% by 2030 — from 17 in 2025 to a central estimate of 8.9 (95% range 3.4–14). A 5-year backtest shows a typical error of ±31.1%, with 60% 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 →
8.9Projected 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 →
3.4–1495% 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 →
±31.1%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 Tennessee is projected to fall about 46% by 2030 — from 17 in 2025 to a central estimate of 8.9 (95% range 3.4–14). A 5-year backtest shows a typical error of ±31.1%, with 60% 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 →
2026104.916
202710.04.615
20289.64.215
20299.23.815
20308.93.414

Member Species In Tennessee

Generalists species in Tennessee.
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 →
Common GrackleIcteridae-88%
House SparrowPasseridae-86%
Rock PigeonColumbidae-63%
Northern MockingbirdMimidae-30%
Mourning DoveColumbidae-16%
Common RavenCorvidae-1%
American CrowCorvidae+8%
European StarlingSturnidae+16%
Brown-headed CowbirdIcteridae+26%
Eurasian Collared-DoveColumbidae+305%
Fish CrowCorvidae20×
House FinchFringillidae56×

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