BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Horned Lark In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGrassland birds

Horned Lark in Southern Rockies / Colorado Plateau has fallen sharply: down 59% on the route-weighted index since 1970.

-59%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 →
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 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 59% 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 54% by 2029 — from 16 in 2024 to a central estimate of 7.4 (95% range 0.00–16). A 5-year backtest shows a typical error of ±38.4%, with 80% of held-out values landing inside the 95% band.

-54%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 →
7.4Projected 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 →
0.00–1695% 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 →
±38.4%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 54% by 2029 — from 16 in 2024 to a central estimate of 7.4 (95% range 0.00–16). A 5-year backtest shows a typical error of ±38.4%, with 80% 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 →
20258.90.0618
20268.50.0017
20278.10.0017
20287.70.0017
20297.40.0016

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
MesitaCOLORADO1212024
San LuisCOLORADO992024
BlancaCOLORADO921987
Corona EastNEW-MEXICO921995
BasinCOLORADO882024
WestwaterUTAH872024
Gilson ButteUTAH852004
Rose WellsARIZONA841978
AntonitoCOLORADO842004
Navajo TrailARIZONA762024
YampaiARIZONA751977
SeligmanARIZONA742024
MoscaCOLORADO742024
NageesiNEW-MEXICO682024
SanosteeNEW-MEXICO682024
OraibiARIZONA642022
ShiprockNEW-MEXICO642024
Willow CreekUTAH632024
Horse SpgsNEW-MEXICO602024
TorreonNEW-MEXICO592024
WaldenCOLORADO582024
Glen CanyonUTAH542024

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