BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Vesper Sparrow In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauGrassland birds

Vesper Sparrow in Southern Rockies / Colorado Plateau has surged: up 94% on the route-weighted index since 1970.

+94%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 →
201Routes 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 Southern Rockies / Colorado Plateau: up 94% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Vesper Sparrow in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2029, near 9.7 (95% range 6.0–13). A 5-year backtest shows a typical error of ±22.7%, with 100% of held-out values landing inside the 95% band.

+8%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 →
9.7Projected 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 →
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 →
±22.7%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 stay roughly flat through 2029, near 9.7 (95% range 6.0–13). A 5-year backtest shows a typical error of ±22.7%, 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 →
20259.55.813
20269.55.813
20279.65.913
20289.65.913
20299.76.013

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 →
WaldenCOLORADO732024
M Warner ResUTAH732024
Sybille CynWYOMING622024
Stinking Lk.NEW-MEXICO601999
Gribbles PrkCOLORADO572024
Mt. Taylor 2NEW-MEXICO492024
DinosaurCOLORADO472024
Dixie NfUTAH462024
VernalUTAH442018
AltonahUTAH422015
DulceNEW-MEXICO412024
Fish Lake NfUTAH412024
Yellowjacket PassCOLORADO372024
San LuisCOLORADO342024
Ant Flat-Ogden CanUTAH342023
BufordWYOMING342024
UncompahgreCOLORADO282024
Mcphee Res.COLORADO282024
Fence LakeNEW-MEXICO282024
DoylevilleCOLORADO262024
AngoraCOLORADO242024
MesitaCOLORADO242024
YampaCOLORADO232023
BlancaCOLORADO231987
AntonitoCOLORADO222004

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