BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Horned Lark In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGrassland birds

Horned Lark in Southern Rockies / Colorado Plateau has fallen sharply: down 61% on the route-weighted index since 1970.

-61%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 →
176Routes In RegionSurvey 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 SignalsNotable 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 Southern Rockies / Colorado Plateau: down 61% on the route-weighted index since 1970.

Horned Lark In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Horned Lark in Southern Rockies / Colorado Plateau is projected to fall about 43% by 2030 — from 13 in 2025 to a central estimate of 7.3 (95% range 0.00–16). A 5-year backtest shows a typical error of ±44.1%, with 100% of held-out values landing inside the 95% band.

-43%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 →
7.3Projected 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 →
0.00–1695% 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 →
±44.1%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 Southern Rockies / Colorado Plateau is projected to fall about 43% by 2030 — from 13 in 2025 to a central estimate of 7.3 (95% range 0.00–16). A 5-year backtest shows a typical error of ±44.1%, 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 →
20268.80.0018
20278.40.0017
20288.00.0017
20297.70.0016
20307.30.0016

Routes In Southern Rockies / Colorado Plateau

Routes recording Horned Lark in Southern Rockies / Colorado Plateau.
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 →
Mt TrumbullARIZONA1671993
Many FarmsARIZONA1582006
DatilNEW-MEXICO1581995
ShiprockNEW-MEXICO952025
BlancaCOLORADO921987
Corona EastNEW-MEXICO921995
MesitaCOLORADO862025
Gilson ButteUTAH852004
Rose WellsARIZONA841978
AntonitoCOLORADO842004
Glen CanyonUTAH832025
Sybille CynWYOMING782025
San LuisCOLORADO772025
YampaiARIZONA751977
MoffatCOLORADO742025
SanosteeNEW-MEXICO732025
MoscaCOLORADO652025
OraibiARIZONA642022
Horse SpgsNEW-MEXICO632025
Willow CreekUTAH632024
Canyon RimsUTAH632025
WestwaterUTAH622025
SeligmanARIZONA572025
Castle ButteARIZONA532025
Fence LakeNEW-MEXICO532025

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