BirdAnalyst
Species · BCR 16 · BBS 2026 Release · 1966–2025

Vesper Sparrow In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGrassland birds

Vesper Sparrow in Southern Rockies / Colorado Plateau has surged: up 93% on the route-weighted index since 1970.

+93%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 →
202Routes 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 Southern Rockies / Colorado Plateau: up 93% on the route-weighted index since 1970.

Vesper Sparrow In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Vesper Sparrow in Southern Rockies / Colorado Plateau is projected to rise about 11% by 2030 — from 8.7 in 2025 to a central estimate of 9.7 (95% range 6.0–13). A 5-year backtest shows a typical error of ±11%, with 100% of held-out values landing inside the 95% band.

+11%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 →
9.7Projected 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 →
6.0–1395% 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 →
±11%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 Southern Rockies / Colorado Plateau is projected to rise about 11% by 2030 — from 8.7 in 2025 to a central estimate of 9.7 (95% range 6.0–13). A 5-year backtest shows a typical error of ±11%, 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 →
20269.55.813
20279.55.913
20289.65.913
20299.66.013
20309.76.013

Routes In Southern Rockies / Colorado Plateau

Routes recording Vesper Sparrow in Southern Rockies / Colorado Plateau.
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 →
M Warner ResUTAH1062025
Sybille CynWYOMING762025
Stinking Lk.NEW-MEXICO601999
Mt. Taylor 2NEW-MEXICO492024
Gribbles PrkCOLORADO472025
Ant Flat-Ogden CanUTAH472025
VernalUTAH442018
Mcphee Res.COLORADO432025
DulceNEW-MEXICO432025
WaldenCOLORADO412025
Beck 2UTAH392025
DinosaurCOLORADO372025
Yellowjacket PassCOLORADO372025
AltonahUTAH342025
Dixie NfUTAH322025
Wilson CreekCOLORADO292025
WarbonnetWYOMING292025
GardnerCOLORADO282025
Fence LakeNEW-MEXICO282025
Skyline DrivUTAH282025
DoylevilleCOLORADO262025
BufordWYOMING252025
YampaCOLORADO232023
BlancaCOLORADO231987
Fish Lake NfUTAH232025

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