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

Lark Sparrow Population Trend in Washington

All statesGrassland birds

Lark Sparrow in Washington has surged: up 765% on the route-weighted index since 1970.

+765%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 →
44Routes 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 Lark Sparrow 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 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 →

Lark Sparrow has surged in Washington: up 765% on the route-weighted index since 1970.

Lark Sparrow Population Forecast in Washington

If the recent trend holds, Lark Sparrow in Washington is projected to rise about 41% by 2030 — from 0.67 in 2025 to a central estimate of 0.94 (95% range 0.38–1.5). A 5-year backtest shows a typical error of ±20.5%, with 100% of held-out values landing inside the 95% band.

+41%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 →
0.94Projected 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 →
0.38–1.595% 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 →
±20.5%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, Lark Sparrow in Washington is projected to rise about 41% by 2030 — from 0.67 in 2025 to a central estimate of 0.94 (95% range 0.38–1.5). A 5-year backtest shows a typical error of ±20.5%, 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 →
20260.890.331.5
20270.900.351.5
20280.920.361.5
20290.930.371.5
20300.940.381.5

Lark Sparrow Survey Routes in Washington

Routes recording Lark Sparrow 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 →
Horn Rapids1720242005
Scootney Reservoir1520252009
Richland1320242006
Snowden819941981
Lake Chelan820251993
Arid Land Er619961988
Mesa620081994
Moses Coulee520251993
Brewster420151977
Moses Lake420221973
Hatton419941992
Hanford Site319961988
Selah320002000
Harrington320121980
Columbia Nwr320221992
Wilbur320161993
Nighthawk320251993
Turnbull Nwr220211996
Wapato220222019
Mercer220221989
Ellensburg220241999
Othello219891985
Keystone220141994
Harwood219971994
Potholes220101997

Lark Sparrow Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoidahoillinoisindianaiowakansaskentuckylouisianaminnesotamississippimissourimontananebraskanevadanew-mexiconorth-dakotaohiooklahomaoregonsouth-dakotatennesseetexasutahwisconsinwyoming

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