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Species · Colorado · BBS 2025 Release · 1966–2024

Grasshopper Sparrow Population Trend in Colorado

All statesGrassland birds

Grasshopper Sparrow in Colorado has fallen sharply: down 63% on the route-weighted index since 1970.

-63%Since 1970
66Routes In State
56Years

Notable Grasshopper Sparrow Trends in Colorado

long arc declinecomputed index

Grasshopper Sparrow has fallen sharply in Colorado: down 63% on the route-weighted index since 1970.

Grasshopper Sparrow Population Forecast in Colorado

If the recent trend holds, Grasshopper Sparrow in Colorado is projected to stay roughly flat through 2029, near 2.0 (95% range 0.00–7.8). A 5-year backtest shows a typical error of ±49.6%, with 100% of held-out values landing inside the 95% band.

+6%Change by 2029
2.0Projected 2029 index
0.00–7.895% range
±49.6%Backtest error
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 index95% low95% high
20252.60.008.3
20262.50.008.2
20272.30.008.0
20282.20.007.9
20292.00.007.8

Grasshopper Sparrow Survey Routes in Colorado

Routes recording Grasshopper Sparrow in Colorado.
Wildhorse L5520241988
Kirk4120231992
Stoneham2920211992
Waverly2720191988
Pinneo2620191973
Campo2520191988
Last Chance2220151970
Nunn1920211995
Abarr1720241968
Rush1520241984
Haswell1420241992
Limon1220241996
Briggsdale1020241968
Neegrande1020241992
Gilpin920241970
Sheridan Lak920161997
Pritchett820241995
Adams Co.720211997
Amherst620241992
Lamar520241973
Two Buttes520151973
Cheyenne520241990
Burlington520232003
Fleming420241968
Arsenal 2420242016

Grasshopper Sparrow Population Trend in Other States

alabamaarizonaarkansascaliforniaconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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