BirdAnalyst
Species · BCR 30 · BBS 2025 Release · 1966–2024

Great Blue Heron In New England / Mid-Atlantic Coast

All regionsNew England / Mid-Atlantic CoastWetland birds

Great Blue Heron in New England / Mid-Atlantic Coast has surged: up 220% on the route-weighted index since 1968.

+220%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 →
149Routes 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 New England / Mid-Atlantic Coast: up 220% on the route-weighted index since 1968.

Great Blue Heron In New England / Mid-Atlantic Coast Population Forecast

If the recent trend holds, Great Blue Heron in New England / Mid-Atlantic Coast is projected to rise about 30% by 2029 — from 1.9 in 2024 to a central estimate of 2.4 (95% range 1.6–3.3). A 5-year backtest shows a typical error of ±56.5%, with 40% of held-out values landing inside the 95% band.

+30%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 →
2.4Projected 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 →
1.6–3.395% 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 →
±56.5%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 New England / Mid-Atlantic Coast is projected to rise about 30% by 2029 — from 1.9 in 2024 to a central estimate of 2.4 (95% range 1.6–3.3). A 5-year backtest shows a typical error of ±56.5%, with 40% 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 →
20252.31.53.2
20262.41.53.2
20272.41.53.2
20282.41.63.2
20292.41.63.3

Routes In New England / Mid-Atlantic Coast

Routes recording Great Blue Heron in New England / Mid-Atlantic Coast.
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 →
St. George'S IslandMARYLAND1142017
HarringtonDELAWARE382024
BlackbirdDELAWARE232024
HongaMARYLAND152024
Colonial PkyVIRGINIA141998
Lowes XrdsDELAWARE131991
HolleyvilleDELAWARE72004
Fair HillMARYLAND61996
Warren 2MASSACHUSETTS62023
Mt PleasantDELAWARE52019
Pepperbox 2DELAWARE52023
Tall TimbersMARYLAND52014
MadisonMARYLAND52024
MarionMASSACHUSETTS52024
BrocktonMASSACHUSETTS52019
N. AndoverMASSACHUSETTS52024
Holleyville 2DELAWARE42018
Grove NeckMARYLAND41996
BrandonVIRGINIA42024
WoodstockCONNECTICUT32007
WilmingtonDELAWARE32014
PepperboxDELAWARE32016
Kittery PtMAINE32023
EastonMARYLAND32019
Forest GroveMARYLAND32023

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