BirdAnalyst
Species · BCR 13 · BBS 2026 Release · 1966–2025

Green Heron In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainWetland birds

Green Heron in Lower Great Lakes / St. Lawrence Plain has held roughly steady: down 9% on the route-weighted index since 1968.

-9%Since 1968TrendPercent 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 →
81Routes 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 →
59YearsYears 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 Green Heron in Lower Great Lakes / St. Lawrence Plain. See the full index history below.

Green Heron In Lower Great Lakes / St. Lawrence Plain Population Forecast

If the recent trend holds, Green Heron in Lower Great Lakes / St. Lawrence Plain is projected to fall about 29% by 2030 — from 0.51 in 2025 to a central estimate of 0.36 (95% range 0.00–0.74). A 5-year backtest shows a typical error of ±17.8%, with 100% of held-out values landing inside the 95% band.

-29%Change by 2030TrendPercent 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 →
0.36Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.7495% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±17.8%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Green Heron in Lower Great Lakes / St. Lawrence Plain is projected to fall about 29% by 2030 — from 0.51 in 2025 to a central estimate of 0.36 (95% range 0.00–0.74). A 5-year backtest shows a typical error of ±17.8%, with 100% of held-out values landing inside the 95% band.19662030
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20260.390.010.77
20270.380.010.76
20280.380.000.75
20290.370.000.75
20300.360.000.74

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Green 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 →
PulaskiNEW-YORK42019
MaysvilleOHIO41994
GhentNEW-YORK32008
NashvilleNEW-YORK32018
OneidaNEW-YORK32009
N VictoryNEW-YORK31969
PittsfieldOHIO32023
GarrettsvileOHIO31990
HiramOHIO32025
Ferris CrnrsPENNSYLVANIA32025
HighlandNEW-YORK22009
AusterlitzNEW-YORK22025
OrleansNEW-YORK22022
Mt MorrisNEW-YORK22019
HamburgNEW-YORK22025
Cherry HillNEW-YORK22013
St JohnsburgNEW-YORK22016
E YoungstownNEW-YORK22022
N Victory 2NEW-YORK22021
WatertownNEW-YORK22011
Alder CreekNEW-YORK22004
OgdensburgNEW-YORK22017
HopkintonNEW-YORK21981
Harris HillNEW-YORK22025
New SomersetOHIO21988

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.