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

Lazuli Bunting Population Trend in Colorado

All statesGeneralists

Lazuli Bunting in Colorado has surged: up 340% on the route-weighted index since 1971.

+340%Since 1971TrendPercent 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 →
81Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Lazuli Bunting Trends in ColoradoNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed 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 →

Lazuli Bunting has surged in Colorado: up 340% on the route-weighted index since 1971.

Lazuli Bunting Population Forecast in Colorado

If the recent trend holds, Lazuli Bunting in Colorado is projected to fall about 24% by 2029 — from 1.2 in 2024 to a central estimate of 0.92 (95% range 0.09–1.8). A 5-year backtest shows a typical error of ±23.5%, with 100% of held-out values landing inside the 95% band.

-24%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 →
0.92Projected 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 →
0.09–1.895% 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 →
±23.5%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, Lazuli Bunting in Colorado is projected to fall about 24% by 2029 — from 1.2 in 2024 to a central estimate of 0.92 (95% range 0.09–1.8). A 5-year backtest shows a typical error of ±23.5%, 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 →
20250.940.101.8
20260.930.101.8
20270.930.091.8
20280.930.091.8
20290.920.091.8

Lazuli Bunting Survey Routes in Colorado

Routes recording Lazuli Bunting in Colorado.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Douglas Pass4220241982
De Beque2220241992
Yampa2120231972
Baxter Pass1820241994
Mesaverde Np820232003
Walsenburg720231996
Willow Peak520211988
Nucla520242000
Stillwater Pass 2520242022
Pagosa Spgs419821971
Wilson Creek420241990
Gribbles Prk420242007
Aspen320241979
Comanche Pk320241994
Ludlow320111998
Animas 2320172005
Cheesman Lk220241971
Colona219961972
Castleton220131988
Crowley220222022
Lake City220021999
Trinchera220191996
Thomasville220181997
Wet Mtns.219981994
Cokedale220241995

Lazuli Bunting Population Trend in Other States

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