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

Horned Lark Population Trend in Colorado

All statesGrassland birds

Horned Lark in Colorado has fallen sharply: down 51% on the route-weighted index since 1970.

-51%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 →
114Routes 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 Horned Lark 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 →

Horned Lark has fallen sharply in Colorado: down 51% on the route-weighted index since 1970.

Horned Lark Population Forecast in Colorado

If the recent trend holds, Horned Lark in Colorado is projected to fall about 41% by 2030 — from 42 in 2025 to a central estimate of 25 (95% range 0.00–68). A 5-year backtest shows a typical error of ±28.5%, with 100% of held-out values landing inside the 95% band.

-41%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 →
25Projected 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 →
0.00–6895% 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 →
±28.5%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, Horned Lark in Colorado is projected to fall about 41% by 2030 — from 42 in 2025 to a central estimate of 25 (95% range 0.00–68). A 5-year backtest shows a typical error of ±28.5%, 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 →
2026310.0074
2027290.0073
2028280.0071
2029260.0069
2030250.0068

Horned Lark Survey Routes in Colorado

Routes recording Horned Lark 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 →
Briggsdale40920251968
Mica Butte39819871968
Haswell31220241992
Last Chance 228920252017
Rockport28220241994
Prospect Val27920001992
Rush27520251983
Edler22720251992
Prospect Valley 221220252001
Stoneham18720251992
Bennett18420251995
Nunn18220251995
Wildhorse L17820251988
Cheyenne17420251990
Adams Co.17320221989
Gordon Creek16620251988
Lamar15720241973
Burlington15120242003
Grover14220241992
Two Buttes13720251973
Fleming13220251968
Limon13220251992
Kirk11520231992
Boyero11420171979
Crowley11220241989

Horned Lark Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniaconnecticutdelawaregeorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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