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

Great Blue Heron In Lower Great Lakes / St. Lawrence Plain

All regionsLower Great Lakes / St. Lawrence PlainWetland birds

Great Blue Heron in Lower Great Lakes / St. Lawrence Plain has surged: up 86% on the route-weighted index since 1968.

+86%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 →
85Routes 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 →
58YearsYears 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 →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Great Blue Heron has surged in Lower Great Lakes / St. Lawrence Plain: up 86% on the route-weighted index since 1968.

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

If the recent trend holds, Great Blue Heron in Lower Great Lakes / St. Lawrence Plain is projected to rise about 75% by 2029 — from 1.0 in 2024 to a central estimate of 1.8 (95% range 0.22–3.4). A 5-year backtest shows a typical error of ±115.3%, with 100% of held-out values landing inside the 95% band.

+75%Change by 2029TrendPercent 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 →
1.8Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.22–3.495% 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 →
±115.3%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, Great Blue Heron in Lower Great Lakes / St. Lawrence Plain is projected to rise about 75% by 2029 — from 1.0 in 2024 to a central estimate of 1.8 (95% range 0.22–3.4). A 5-year backtest shows a typical error of ±115.3%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20251.80.203.4
20261.80.203.4
20271.80.213.4
20281.80.213.4
20291.80.223.4

Routes In Lower Great Lakes / St. Lawrence Plain

Routes recording Great Blue 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 →
RomulusNEW-YORK172000
PeruOHIO141978
HighlandNEW-YORK92022
WaddingtonNEW-YORK81998
West SenecaNEW-YORK52004
BalmatNEW-YORK51997
New SomersetOHIO51993
SheridanNEW-YORK41998
LenoxOHIO42024
TeeplevillePENNSYLVANIA42024
TrumansburgNEW-YORK32024
NashvilleNEW-YORK32018
Alder CreekNEW-YORK32004
EllenburgNEW-YORK32006
NaplesNEW-YORK32024
PhiladelphiaNEW-YORK32024
N VictoryNEW-YORK31969
MiddlefieldOHIO32017
HebronOHIO32024
MacdougallNEW-YORK22023
BranchportNEW-YORK22023
HamburgNEW-YORK22023
CastileNEW-YORK22024
Cicero CtrNEW-YORK22024
ClintonNEW-YORK22013

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