BirdAnalyst
Species · Colorado · BBS 2025 Release · 1966–2024

Savannah Sparrow Population Trend in Colorado

All statesGrassland birds

Savannah Sparrow in Colorado has increased: up 49% on the route-weighted index since 1970.

+49%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 →
86Routes 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 →
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 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 27% by 2029 — from 1.7 in 2024 to a central estimate of 2.2 (95% range 0.00–5.1). A 5-year backtest shows a typical error of ±34.4%, with 100% of held-out values landing inside the 95% band.

+27%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 →
2.2Projected 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 →
0.00–5.195% 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 →
±34.4%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, Savannah Sparrow in Colorado is projected to rise about 27% by 2029 — from 1.7 in 2024 to a central estimate of 2.2 (95% range 0.00–5.1). A 5-year backtest shows a typical error of ±34.4%, 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 →
20252.10.005.1
20262.20.005.1
20272.20.005.1
20282.20.005.1
20292.20.005.1

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 →
Walden4320241990
Yampa4220231969
Castleton2720241988
Steamboat L.1920241996
Doyleville1720241988
Weston Pass1720001994
Heeney1420192017
Parlin1120231968
Gribbles Prk1120241996
Abarr819691969
Ragged Mtn.720191994
Buford620241973
Colona520121972
Adams Co.520192016
Piceance Basin520042004
Stillwater Pass 2520242010
Maybell420241996
Wildhorse L420002000
Tarryall420231988
Uncompahgre419981994
Buffalo Park420232006
Como419991994
Cochetopa Pass420241998
Falfa320221977
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 2026-05-22.