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

Lark Bunting Population Trend in Colorado

All statesGrassland birds

Lark Bunting in Colorado has collapsed: down 86% on the route-weighted index since 1970.

-86%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 →
78Routes 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 →
56YearsYears 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 86% 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 23% by 2029 — from 8.6 in 2024 to a central estimate of 6.6 (95% range 0.00–51). A 5-year backtest shows a typical error of ±66.6%, 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 →
6.6Projected 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 →
0.00–5195% 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 →
±66.6%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, Lark Bunting in Colorado is projected to fall about 23% by 2029 — from 8.6 in 2024 to a central estimate of 6.6 (95% range 0.00–51). A 5-year backtest shows a typical error of ±66.6%, 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 →
2025120.0056
2026100.0055
20279.20.0054
20287.90.0052
20296.60.0051

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 →
Nunn26220211995
Stoneham21420211992
Karval19820191995
Doyle Bridge18419951992
Kirk17420231992
Two Buttes16920151973
Limon14320241992
Last Chance11220161968
Last Chance 210320242017
Boyero9220171979
Briggsdale9020241968
Wildhorse L7820241988
Fleming7420231968
Rockport5420241994
Gordon Creek4320241988
Mica Butte3919871968
Amherst3920241992
Sheridan Lak3820161995
Prospect Valley 23820232001
Rush3720241983
Arsenal 23720242016
Grover3320241992
Haswell3120241992
Edison2820241988
Gilpin2520241970

Lark Bunting Population Trend in Other States

arizonacaliforniaidahoiowakansasminnesotamissourimontananebraskanew-mexiconorth-dakotaoklahomasouth-dakotatexasutahwyoming

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