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

Generalists In Colorado

All statesColorado

14 species in this guild. As a group they are -41%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 1970.

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 declined in Colorado, down 41% since 1970.

Generalists In Colorado Population Forecast

If the recent trend holds, Generalists in Colorado is projected to fall about 24% by 2030 — from 7.7 in 2025 to a central estimate of 5.9 (95% range 3.1–8.7). A 5-year backtest shows a typical error of ±10.6%, with 100% of held-out values landing inside the 95% band.

-24%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 →
5.9Projected 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 →
3.1–8.795% 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 →
±10.6%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 Colorado is projected to fall about 24% by 2030 — from 7.7 in 2025 to a central estimate of 5.9 (95% range 3.1–8.7). A 5-year backtest shows a typical error of ±10.6%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20266.43.69.2
20276.33.59.1
20286.13.38.9
20296.03.28.8
20305.93.18.7

Member Species In Colorado

Generalists species in Colorado.
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-75%
Brewer's BlackbirdIcteridae-58%
Black-billed MagpieCorvidae-48%
American CrowCorvidae-26%
Mourning DoveColumbidae-18%
Rock PigeonColumbidae-17%
European StarlingSturnidae+27%
House FinchFringillidae+76%
Northern MockingbirdMimidae+128%
Common GrackleIcteridae+193%
Brown-headed CowbirdIcteridae+415%
Chihuahuan RavenCorvidae+461%
Common RavenCorvidae+716%
Eurasian Collared-DoveColumbidae27×

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