BirdAnalyst
Guild · Colorado · BBS 2025 Release · 1966–2024

Generalists In Colorado

All statesColorado

88 species in this guild. As a group they are -43%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 43% since 1970.

Forecast

If the recent trend holds, Generalists in Colorado is projected to fall about 23% by 2029 — from 2.6 in 2024 to a central estimate of 2.0 (95% range 1.2–2.7). A 5-year backtest shows a typical error of ±15.4%, with 100% of held-out values landing inside the 95% band.

-23%Change by 2029TrendPercent 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 →
2.0Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
1.2–2.795% 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 →
±15.4%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, Generalists in Colorado is projected to fall about 23% by 2029 — from 2.6 in 2024 to a central estimate of 2.0 (95% range 1.2–2.7). A 5-year backtest shows a typical error of ±15.4%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20252.11.42.9
20262.11.32.9
20272.11.32.8
20282.01.22.8
20292.01.22.7

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 →
Chestnut-collared LongspurCalcariidae-95%
Band-tailed PigeonColumbidae-94%
Greater Sage-GrousePhasianidae-84%
Northern HarrierAccipitridae-83%
Brown ThrasherMimidae-81%
Dusky GrousePhasianidae-78%
Yellow-billed CuckooCuculidae-77%
Gunnison Sage-GrousePhasianidae-77%
House SparrowPasseridae-76%
Belted KingfisherAlcedinidae-76%
Baltimore OrioleIcteridae-74%
Sharp-shinned HawkAccipitridae-70%
Short-eared OwlStrigidae-69%
Loggerhead ShrikeLaniidae-69%
Prairie FalconFalconidae-67%
ChukarPhasianidae-66%
Scaled QuailOdontophoridae-65%
Indigo BuntingCardinalidae-64%
American GoshawkAccipitridae-60%
Burrowing OwlStrigidae-59%
Ferruginous HawkAccipitridae-58%
Brewer's BlackbirdIcteridae-55%
Great Horned OwlStrigidae-51%
Black-billed MagpieCorvidae-46%
American DipperCinclidae-46%
Canyon TowheePasserellidae-41%
Rock PigeonColumbidae-35%
Red-winged BlackbirdIcteridae-31%
American KestrelFalconidae-29%
Steller's JayCorvidae-26%
American CrowCorvidae-25%
Gray CatbirdMimidae-23%
Mourning DoveColumbidae-21%
Cooper's HawkAccipitridae-21%
Golden EagleAccipitridae-16%
Song SparrowPasserellidae-13%
Orchard OrioleIcteridae-8%
Northern Pygmy-OwlStrigidae-5%
Broad-tailed HummingbirdTrochilidae-5%
Yellow-breasted ChatIcteriidae+3%
Pine SiskinFringillidae+10%
European StarlingSturnidae+20%
Pine GrosbeakFringillidae+26%
Blue JayCorvidae+27%
Sagebrush SparrowPasserellidae+40%
Bald EagleAccipitridae+40%
Evening GrosbeakFringillidae+43%
Swainson's HawkAccipitridae+44%
Canada JayCorvidae+47%
Thick-billed LongspurCalcariidae+60%
House FinchFringillidae+64%
Black-chinned HummingbirdTrochilidae+68%
Green-tailed TowheePasserellidae+69%
Blue GrosbeakCardinalidae+74%
Brewer's SparrowPasserellidae+103%
Woodhouse's Scrub-JayCorvidae+110%
Bullock's OrioleIcteridae+121%
Western TanagerCardinalidae+122%
Lincoln's SparrowPasserellidae+141%
Chipping SparrowPasserellidae+152%
Red CrossbillFringillidae+161%
Common GrackleIcteridae+176%
American GoldfinchFringillidae+186%
Northern MockingbirdMimidae+207%
Black-headed GrosbeakCardinalidae+216%
Great-tailed GrackleIcteridae+239%
OspreyPandionidae+247%
Peregrine FalconFalconidae+257%
Pinyon JayCorvidae+260%
BushtitAegithalidae+261%
Chihuahuan RavenCorvidae+285%
American PipitMotacillidae+311%
Lesser GoldfinchFringillidae+313%
Lazuli BuntingCardinalidae+340%
Yellow-headed BlackbirdIcteridae+353%
Turkey VultureCathartidae+359%
Cedar WaxwingBombycillidae+371%
Red-tailed HawkAccipitridae+372%
Brown-headed CowbirdIcteridae+391%
Fox SparrowPasserellidae+395%
White-crowned SparrowPasserellidae+440%
Cassin's FinchFringillidae+514%
Common RavenCorvidae+717%
Wild TurkeyPhasianidae+779%
Sage ThrasherMimidae+798%
Spotted TowheePasserellidae19×
Clark's NutcrackerCorvidae20×
Eurasian Collared-DoveColumbidae26×

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.