BirdAnalyst
Species · BCR 23 · BBS 2026 Release · 1966–2025

Great Blue Heron In Prairie Hardwood Transition

All regionsPrairie Hardwood TransitionWetland birds

Great Blue Heron in Prairie Hardwood Transition has held roughly steady: down 3% on the route-weighted index since 1968.

-3%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 →
161Routes 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 Great Blue Heron in Prairie Hardwood Transition. See the full index history below.

Great Blue Heron In Prairie Hardwood Transition Population Forecast

If the recent trend holds, Great Blue Heron in Prairie Hardwood Transition is projected to rise about 45% by 2030 — from 1.1 in 2025 to a central estimate of 1.6 (95% range 0.33–2.8). A 5-year backtest shows a typical error of ±46.1%, with 100% of held-out values landing inside the 95% band.

+45%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 →
1.6Projected 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 →
0.33–2.895% 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 →
±46.1%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 Prairie Hardwood Transition is projected to rise about 45% by 2030 — from 1.1 in 2025 to a central estimate of 1.6 (95% range 0.33–2.8). A 5-year backtest shows a typical error of ±46.1%, 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 →
20261.60.372.8
20271.60.362.8
20281.60.352.8
20291.60.342.8
20301.60.332.8

Routes In Prairie Hardwood Transition

Routes recording Great Blue Heron in Prairie Hardwood Transition.
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 →
HatfieldWISCONSIN211998
PackertownINDIANA162004
GraytownOHIO161984
Drayton PlnsMICHIGAN121987
BismarkOHIO71995
OmroWISCONSIN72001
Pt WashingtnWISCONSIN62024
Cherry Val 2ILLINOIS52018
North BranchMICHIGAN51998
HudsonWISCONSIN52025
TyreMICHIGAN41995
RochesterMICHIGAN42025
MinnetonkaMINNESOTA42025
PrincetonMINNESOTA42024
Sherburne NrMINNESOTA42025
N BaltimoreOHIO42018
Prairie Du ChienWISCONSIN42025
Mukwonago 2WISCONSIN42025
KewannaINDIANA32018
Indiana DuneINDIANA32022
Big Blue LkMICHIGAN32025
LawrenceMICHIGAN32021
MontereyMICHIGAN32024
MottvilleMICHIGAN32025
HoltMICHIGAN32025

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