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

Little Blue Heron Population Trend in Illinois

All statesWetland birds

Little Blue Heron in Illinois has collapsed: down 86% on the route-weighted index since 1971.

-86%Since 1971
12Routes In State
49Years

Notable Little Blue Heron Trends in Illinois

long arc declinecomputed index

Little Blue Heron has collapsed in Illinois: down 86% on the route-weighted index since 1971.

Little Blue Heron Population Forecast in Illinois

If the recent trend holds, Little Blue Heron in Illinois is projected to stay roughly flat through 2028, near 0.17 (95% range 0.00–0.48). A 5-year backtest shows a typical error of ±1100.3%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2028
0.17Projected 2028 index
0.00–0.4895% range
±1100.3%Backtest error
19672028
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
20240.170.000.49
20250.170.000.49
20260.170.000.49
20270.170.000.49
20280.170.000.48

Little Blue Heron Survey Routes in Illinois

Routes recording Little Blue Heron in Illinois.
Belknap920112011
Bremen620172002
Pulaski420111970
Columbia320231987
Mascoutah Lk320151972
Sandusky220112001
Belleview119851976
Jamestown120121991
St Morgan120221967
Mt Vernon120062006
Olney120002000
Beaverdam Lk119941970

Little Blue Heron Population Trend in Other States

alabamaarkansasconnecticutdelawarefloridageorgiakansaskentuckylouisianamarylandmassachusettsmississippimissourinew-jerseynew-yorknorth-carolinanorth-dakotaoklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvirginia

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