BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Lark Sparrow In Great Basin

All regionsGreat BasinGrassland birds

Lark Sparrow in Great Basin has surged: up 163% on the route-weighted index since 1970.

+163%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 →
207Routes 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 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 Great Basin: up 163% on the route-weighted index since 1970.

Lark Sparrow In Great Basin Population Forecast

If the recent trend holds, Lark Sparrow in Great Basin is projected to fall about 11% by 2029 — from 4.5 in 2024 to a central estimate of 4.0 (95% range 2.5–5.5). A 5-year backtest shows a typical error of ±18.9%, with 60% of held-out values landing inside the 95% band.

-11%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 →
4.0Projected 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 →
2.5–5.595% 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 →
±18.9%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, Lark Sparrow in Great Basin is projected to fall about 11% by 2029 — from 4.5 in 2024 to a central estimate of 4.0 (95% range 2.5–5.5). A 5-year backtest shows a typical error of ±18.9%, with 60% 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 →
20253.92.45.4
20263.92.45.4
20273.92.45.4
20283.92.45.5
20294.02.55.5

Routes In Great Basin

Routes recording Lark Sparrow in Great Basin.
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 →
PromontoryUTAH772024
LeamingtonUTAH752017
Chimney Res.NEVADA612024
Trout CreekOREGON572021
Alvord LakeOREGON562024
Majors PlaceNEVADA352024
WendoverUTAH352011
RanchograndeNEVADA252024
IngallsCALIFORNIA221999
Pine CreekUTAH222023
GrantsvilleUTAH202024
Piute MdwsNEVADA192024
Catlow RimOREGON192024
Goose Creek Mtn.UTAH192023
MidasNEVADA182024
SheavilleOREGON182024
Horn RapidsWASHINGTON172024
Glenns FerryIDAHO161986
Harney LakeOREGON152024
Three ForksOREGON142024
Timpie SpgUTAH142003
Gold HillUTAH132024
VernonUTAH132024
CliveUTAH132013
RichlandWASHINGTON132024

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