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

Horned Lark Population Trend in Oregon

All statesGrassland birds

Horned Lark in Oregon has risen sharply: up 57% on the route-weighted index since 1970.

+57%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 →
65Routes 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 OregonNotable 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 increasecomputed 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 risen sharply in Oregon: up 57% on the route-weighted index since 1970.

Horned Lark Population Forecast in Oregon

If the recent trend holds, Horned Lark in Oregon is projected to fall about 54% by 2030 — from 17 in 2025 to a central estimate of 7.9 (95% range 0.00–18). A 5-year backtest shows a typical error of ±52.2%, with 60% of held-out values landing inside the 95% band.

-54%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 →
7.9Projected 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 →
0.00–1895% 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 →
±52.2%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 Oregon is projected to fall about 54% by 2030 — from 17 in 2025 to a central estimate of 7.9 (95% range 0.00–18). A 5-year backtest shows a typical error of ±52.2%, with 60% 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 →
20268.20.0018
20278.20.0018
20288.10.0018
20298.00.0018
20307.90.0018

Horned Lark Survey Routes in Oregon

Routes recording Horned Lark in Oregon.
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 →
Bowden Hills35420251999
Malheur Res.27120232022
Battle Mtn19920251985
Willow Spg19819711969
Lone Rock16820241968
Cecil15320251998
Montague14220251974
Three Forks13620252003
Blitzen 213520251994
Crowley12720251983
Blitzen9919931971
Adrian8920251984
Zumwalt8020051995
Lookout Lake6719941985
Mikkalo5720251996
Flook Lake5620251994
Umatilla4620251988
Eightmile4220251982
Princeton3319851972
Wagontire2920251968
Catlow Rim2820251993
Malheur Nwr2720221986
Pendleton2520251972
Green Mtn.2520251994
Crooked Riv.2220251994

Horned Lark Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawaregeorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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