BirdAnalyst
Species · Colorado · BBS 2026 Release · 1966–2025

Savannah Sparrow Population Trend in Colorado

All statesGrassland birds

Savannah Sparrow in Colorado has increased: up 37% on the route-weighted index since 1970.

+37%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 →
87Routes In StateSurvey 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 Savannah Sparrow Trends in ColoradoNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

No notable trend signals for Savannah Sparrow in Colorado. See the full index history below.

Savannah Sparrow Population Forecast in Colorado

If the recent trend holds, Savannah Sparrow in Colorado is projected to rise about 53% by 2030 — from 1.4 in 2025 to a central estimate of 2.1 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±38.8%, with 100% of held-out values landing inside the 95% band.

+53%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 →
2.1Projected 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 →
0.00–5.095% 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 →
±38.8%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, Savannah Sparrow in Colorado is projected to rise about 53% by 2030 — from 1.4 in 2025 to a central estimate of 2.1 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±38.8%, 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 →
20262.10.005.0
20272.10.005.0
20282.10.005.0
20292.10.005.0
20302.10.005.0

Savannah Sparrow Survey Routes in Colorado

Routes recording Savannah Sparrow in Colorado.
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 →
Yampa4220231969
Walden3820251990
Castleton2420251988
Weston Pass1720001994
Heeney1420192017
Steamboat L.1320251996
Doyleville1020251988
Gribbles Prk1020251996
Abarr819691969
Paonia820251992
Parlin720251968
Ragged Mtn.720191994
Buford620241973
Cochetopa Pass620251998
Stillwater Pass 2620252010
Colona520121972
Moffat520251977
Adams Co.520192016
Piceance Basin520042004
Heeney 2520252025
Maybell420241996
Uncompahgre419981994
Buffalo Park420232006
Como419991994
Fruita320071999

Savannah Sparrow Population Trend in Other States

alaskaarizonacaliforniaconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooregonpennsylvaniarhode-islandsouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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