BirdAnalyst
Species · BCR 13 · BBS 2025 Release · 1966–2024

Black-crowned Night Heron In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainWetland birds

Black-crowned Night Heron in Lower Great Lakes / St. Lawrence Plain has declined: down 47% on the route-weighted index since 1971.

-47%Since 1971TrendPercent 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 →
15Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
16YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 Black-crowned Night Heron in Lower Great Lakes / St. Lawrence Plain. See the full index history below.

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Black-crowned Night Heron in Lower Great Lakes / St. Lawrence Plain.
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 →
CatskillsNEW-YORK41990
Mt MorrisNEW-YORK31975
SheridanNEW-YORK21972
E YoungstownNEW-YORK21989
Cicero CtrNEW-YORK21966
PeruOHIO21978
OrleansNEW-YORK11972
HamburgNEW-YORK11977
West SenecaNEW-YORK11981
WatertownNEW-YORK11971
LenoxOHIO12022
LattasburgOHIO11976
EspyvillePENNSYLVANIA11998
Ferris CrnrsPENNSYLVANIA11991
Grand IsleVERMONT11979

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