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

American Bittern Population Trend in Colorado

All statesWetland birds

American Bittern in Colorado has collapsed: down 81% on the route-weighted index since 1984.

-81%Since 1984
7Routes In State
35Years

Notable American Bittern Trends in Colorado

long arc declinecomputed index

American Bittern has collapsed in Colorado: down 81% on the route-weighted index since 1984.

American Bittern Population Forecast in Colorado

If the recent trend holds, American Bittern in Colorado is projected to stay roughly flat through 2029, near 0.01 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±111.2%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2029
0.01Projected 2029 index
0.00–0.1495% range
±111.2%Backtest error
19732029
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
20250.020.000.15
20260.020.000.14
20270.020.000.14
20280.020.000.14
20290.010.000.14

American Bittern Survey Routes in Colorado

Routes recording American Bittern in Colorado.
Alamosa220241988
San Luis220111998
Mcphee Res.120172017
Last Chance119961973
Lay120002000
Moffat119951983
Fort Morgan120101999

American Bittern Population Trend in Other States

alaskacaliforniaconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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