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Species · Pennsylvania · BBS 2025 Release · 1966–2024

Black-crowned Night Heron Population Trend in Pennsylvania

All statesWetland birds

Black-crowned Night Heron in Pennsylvania has declined: down 46% on the route-weighted index since 1970.

-46%Since 1970
24Routes In State
44Years

Notable Black-crowned Night Heron Trends in Pennsylvania

No notable trend signals for Black-crowned Night Heron in Pennsylvania. See the full index history below.

Black-crowned Night Heron Population Forecast in Pennsylvania

If the recent trend holds, Black-crowned Night Heron in Pennsylvania is projected to stay roughly flat through 2029, near 0.02 (95% range 0.00–0.07). A 5-year backtest shows a typical error of ±128.8%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2029
0.02Projected 2029 index
0.00–0.0795% range
±128.8%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
20250.030.000.07
20260.030.000.07
20270.030.000.07
20280.020.000.07
20290.020.000.07

Black-crowned Night Heron Survey Routes in Pennsylvania

Routes recording Black-crowned Night Heron in Pennsylvania.
Ephrata519811981
Quakertown419731973
Williamsburg320222022
Scheafferstn319751969
Austinville219701970
Schaefferstown 2220132013
Peters Mt219931993
Sporting Hil219771977
Brunnerville219881977
Espyville119981998
Ferris Crnrs119911991
Leola120231999
Pocono Summit119681968
Landisburg119911978
Elizabethvil120241996
Mount Joy119961978
Bendersville120102010
Jacobus120151987
Clear Spring120172017
Mifflintown120132013
Middletown120071976
Mt Gretna119911970
Pottstown119791979
Labott119791970

Black-crowned Night Heron Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonrhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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