BirdAnalyst
Species · BCR 28 · BBS 2025 Release · 1966–2024

Great Blue Heron In Appalachian Mountains

All regionsAppalachian MountainsWetland birds

Great Blue Heron in Appalachian Mountains has surged: up 437% on the route-weighted index since 1968.

+437%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 →
340Routes 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 Appalachian Mountains: up 437% on the route-weighted index since 1968.

Great Blue Heron In Appalachian Mountains Population Forecast

If the recent trend holds, Great Blue Heron in Appalachian Mountains is projected to rise about 63% by 2029 — from 0.57 in 2024 to a central estimate of 0.94 (95% range 0.56–1.3). A 5-year backtest shows a typical error of ±67.8%, with 20% of held-out values landing inside the 95% band.

+63%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 →
0.94Projected 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 →
0.56–1.395% 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 →
±67.8%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, Great Blue Heron in Appalachian Mountains is projected to rise about 63% by 2029 — from 0.57 in 2024 to a central estimate of 0.94 (95% range 0.56–1.3). A 5-year backtest shows a typical error of ±67.8%, with 20% 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 →
20250.890.521.3
20260.900.531.3
20270.910.541.3
20280.920.551.3
20290.940.561.3

Routes In Appalachian Mountains

Routes recording Great Blue Heron in Appalachian Mountains.
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 →
RiversideALABAMA412013
HanoverWEST-VIRGINIA122021
GreensportALABAMA72024
Signal MtnTENNESSEE72024
Loft MtnVIRGINIA62009
StevensonALABAMA52024
BeaverPENNSYLVANIA52023
GuntersvilleALABAMA42017
TalladegaALABAMA42024
HopeNEW-JERSEY41993
Warwick 2NEW-YORK42013
Plesant GrovPENNSYLVANIA42022
DrehersvillePENNSYLVANIA41998
Drehersville 2PENNSYLVANIA42024
Lost RiverWEST-VIRGINIA42023
SummittALABAMA31978
BrooksvilleALABAMA32023
Kehoe 2KENTUCKY32023
JenningsMARYLAND32023
RamseysburgNEW-JERSEY32024
Oxford 2NEW-YORK32024
BrevardNORTH-CAROLINA32019
AdamsvilleOHIO31989
SmithfieldOHIO32023
Mohican S.F.OHIO32024

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