BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Vesper Sparrow In Great Basin

All regionsGreat BasinGrassland birds

Vesper Sparrow in Great Basin has surged: up 198% on the route-weighted index since 1970.

+198%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 →
212Routes 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 →
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 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 →

Vesper Sparrow has surged in Great Basin: up 198% on the route-weighted index since 1970.

Vesper Sparrow In Great Basin Population Forecast

If the recent trend holds, Vesper Sparrow in Great Basin is projected to rise about 17% by 2030 — from 8.5 in 2025 to a central estimate of 10 (95% range 4.8–15). A 5-year backtest shows a typical error of ±41.1%, with 100% of held-out values landing inside the 95% band.

+17%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 →
10Projected 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 →
4.8–1595% 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 →
±41.1%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, Vesper Sparrow in Great Basin is projected to rise about 17% by 2030 — from 8.5 in 2025 to a central estimate of 10 (95% range 4.8–15). A 5-year backtest shows a typical error of ±41.1%, 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 →
20269.84.615
20279.94.715
20289.94.715
202910.04.815
2030104.815

Routes In Great Basin

Routes recording Vesper 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 →
ZumwaltOREGON1272005
Charleston ReservoirNEVADA952024
Blitzen 2OREGON652025
Battle MtnOREGON642025
RanchograndeNEVADA602024
HenryIDAHO591983
Humboldt Nf 2NEVADA592025
Daniels ResIDAHO582025
BuchananOREGON562025
Humboldt NfNEVADA532019
Flook LakeOREGON482025
PrincetonOREGON451985
HarringtonWASHINGTON362012
CareyIDAHO352025
Dinner StaNEVADA351993
Catlow RimOREGON352025
Moses CouleeWASHINGTON342025
Iron SpringsIDAHO312024
SelahWASHINGTON312025
Sheldon NwrNEVADA302019
RirieIDAHO292025
MidasNEVADA292025
Bald Mtn.NEVADA292025
Blackft ResIDAHO262018
BlitzenOREGON261993

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