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

Lark Bunting Population Trend in Colorado

All statesGrassland birds

Lark Bunting in Colorado has collapsed: down 80% on the route-weighted index since 1970.

-80%Since 1970TrendPercent 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 →
79Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Lark 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 declinecomputed 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 →

Lark Bunting has collapsed in Colorado: down 80% on the route-weighted index since 1970.

Lark Bunting Population Forecast in Colorado

If the recent trend holds, Lark Bunting in Colorado is projected to fall about 73% by 2030 — from 24 in 2025 to a central estimate of 6.3 (95% range 0.00–50). A 5-year backtest shows a typical error of ±74.9%, with 100% of held-out values landing inside the 95% band.

-73%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 →
6.3Projected 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 →
0.00–5095% 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 →
±74.9%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, Lark Bunting in Colorado is projected to fall about 73% by 2030 — from 24 in 2025 to a central estimate of 6.3 (95% range 0.00–50). A 5-year backtest shows a typical error of ±74.9%, 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 →
2026110.0055
2027100.0054
20288.80.0053
20297.50.0052
20306.30.0050

Lark Bunting Survey Routes in Colorado

Routes recording Lark 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 →
Briggsdale29720251968
Rush27020251983
Limon26720251992
Karval23420251995
Doyle Bridge18419951992
Kirk17420231992
Timpas16820251995
Edison16220251988
Stoneham13120251992
Last Chance11220161968
Nunn11020251995
Last Chance 29820252017
Gordon Creek9720251988
Arsenal 29520252016
Boyero9220171979
Prospect Valley 28420252001
Flagler8320251997
Wildhorse L7120251988
Ellicott6220251994
Two Buttes6120251973
Rockport5420241994
San Luis4420251992
Gilpin4120251970
Mica Butte3919871968
Amherst3920241992

Lark Bunting Population Trend in Other States

arizonacaliforniaidahoiowakansasminnesotamissourimontananebraskanew-mexiconorth-dakotaoklahomasouth-dakotatexasutahwyoming

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