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

Horned Lark Population Trend in Washington

All statesGrassland birds

Horned Lark in Washington has fallen sharply: down 53% on the route-weighted index since 1970.

-53%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 →
47Routes 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 WashingtonNotable 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 Washington: down 53% on the route-weighted index since 1970.

Horned Lark Population Forecast in Washington

If the recent trend holds, Horned Lark in Washington is projected to rise about 29% by 2030 — from 11 in 2025 to a central estimate of 14 (95% range 0.53–28). A 5-year backtest shows a typical error of ±13.9%, with 100% of held-out values landing inside the 95% band.

+29%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 →
14Projected 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 →
0.53–2895% 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 →
±13.9%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 Washington is projected to rise about 29% by 2030 — from 11 in 2025 to a central estimate of 14 (95% range 0.53–28). A 5-year backtest shows a typical error of ±13.9%, 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 →
2026151.229
2027151.129
2028150.8829
2029150.7029
2030140.5328

Horned Lark Survey Routes in Washington

Routes recording Horned Lark in Washington.
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 →
Arid Land Er32919961988
Harrington18120121973
Richland16720242006
Hatton15019941992
Hanford Site13919961988
Horn Rapids12720242005
Hartline10620241994
Keystone10320251994
Bickleton9820191980
Wilbur8320251983
Sulphur8220221995
Asotin8120251981
Prescott7320221981
Selah5920252000
Reardan5420251968
Connell5420151968
Odessa5320251993
Mercer4920221968
Moses Coulee3720251993
Pomeroy3420241992
Malden3220251998
Ewan 23120252023
Walla Walla3119931993
Ewan2820191983
Quincy1320241981

Horned Lark Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawaregeorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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