BirdAnalyst
Species · Washington · BBS 2025 Release · 1966–2024

Horned Lark Population Trend in Washington

All statesGrassland birds

Horned Lark in Washington has declined: down 47% on the route-weighted index since 1970.

-47%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 →
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 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 →

No notable trend signals for Horned Lark in Washington. See the full index history below.

Horned Lark Population Forecast in Washington

If the recent trend holds, Horned Lark in Washington is projected to stay roughly flat through 2029, near 15 (95% range 0.98–29). A 5-year backtest shows a typical error of ±8.5%, with 100% of held-out values landing inside the 95% band.

-10%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 →
15Projected 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 →
0.98–2995% 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 →
±8.5%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 Washington is projected to stay roughly flat through 2029, near 15 (95% range 0.98–29). A 5-year backtest shows a typical error of ±8.5%, with 100% 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 →
2025161.730
2026151.529
2027151.329
2028151.229
2029150.9829

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
Keystone11620241994
Wilbur10720241983
Hartline10620241994
Bickleton9820191980
Sulphur8220221995
Prescott7320221981
Reardan6720241968
Odessa6720241993
Asotin6620241981
Connell5420151968
Malden5020241998
Mercer4920221968
Selah3920232000
Pomeroy3420241992
Walla Walla3119931993
Ewan2820191983
Ewan 22020242023
Quincy1320241981
Moses Coulee920231993

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 2026-05-22.