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

Fox Sparrow In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauForest birds

Fox Sparrow in Southern Rockies / Colorado Plateau has surged: up 856% on the route-weighted index since 1972.

+856%Since 1972TrendPercent 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 →
69Routes 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 →
52YearsYears 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 →

Fox Sparrow has surged in Southern Rockies / Colorado Plateau: up 856% on the route-weighted index since 1972.

Fox Sparrow In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Fox Sparrow in Southern Rockies / Colorado Plateau is projected to rise about 22% by 2030 — from 0.49 in 2025 to a central estimate of 0.59 (95% range 0.25–0.93). A 5-year backtest shows a typical error of ±56.9%, with 80% of held-out values landing inside the 95% band.

+22%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 →
0.59Projected 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 →
0.25–0.9395% 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 →
±56.9%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, Fox Sparrow in Southern Rockies / Colorado Plateau is projected to rise about 22% by 2030 — from 0.49 in 2025 to a central estimate of 0.59 (95% range 0.25–0.93). A 5-year backtest shows a typical error of ±56.9%, with 80% 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 →
20260.570.230.91
20270.570.230.91
20280.580.240.92
20290.590.250.93
20300.590.250.93

Routes In Southern Rockies / Colorado Plateau

Routes recording Fox 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 →
Uintah NfUTAH131994
Dolores RivCOLORADO72025
Lost Cr. ResUTAH72015
TincupCOLORADO52025
Logan CanyonUTAH52019
Red CliffCOLORADO42025
CastletonCOLORADO42025
ComoCOLORADO42025
SoapstoneUTAH42025
Fox ParkWYOMING42025
BufordCOLORADO32022
Lost LakeCOLORADO32025
Groundhog RsCOLORADO32025
Fox CreekCOLORADO32011
Ragged Mtn.COLORADO32025
Weston PassCOLORADO32000
Rifle FallsCOLORADO32021
Lizard Head PassCOLORADO32025
GooseberryUTAH32025
FerronUTAH32025
ColonaCOLORADO22012
Wilson CreekCOLORADO22025
UncompahgreCOLORADO22023
DoylevilleCOLORADO22023
Lake CityCOLORADO22003

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