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

Vesper Sparrow In Great Basin

All regionsGreat BasinGrassland birds

Vesper Sparrow in Great Basin has surged: up 172% on the route-weighted index since 1970.

+172%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 →
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 →

Vesper Sparrow has surged in Great Basin: up 172% 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 20% by 2029 — from 8.4 in 2024 to a central estimate of 10 (95% range 4.8–15). A 5-year backtest shows a typical error of ±44.4%, with 100% of held-out values landing inside the 95% band.

+20%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 →
10Projected 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 →
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 →
±44.4%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 20% by 2029 — from 8.4 in 2024 to a central estimate of 10 (95% range 4.8–15). A 5-year backtest shows a typical error of ±44.4%, 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 →
20259.94.615
20269.94.715
202710.04.715
2028104.815
2029104.815

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 2OREGON802024
RanchograndeNEVADA602024
HenryIDAHO591983
DuboisIDAHO582024
Flook LakeOREGON552024
Humboldt NfNEVADA532019
BuchananOREGON532024
Humboldt Nf 2NEVADA502024
PrincetonOREGON451985
Daniels ResIDAHO412019
LynnUTAH412023
Goose Creek Mtn.UTAH392023
HarringtonWASHINGTON362012
Dinner StaNEVADA351993
Bald Mtn.NEVADA342024
MidasNEVADA332024
Iron SpringsIDAHO312024
SheavilleOREGON312024
Sheldon NwrNEVADA302019
TriangleIDAHO262024
Blackft ResIDAHO262018
BlitzenOREGON261993
Catlow RimOREGON262024

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