BirdAnalyst
Species · BCR 22 · BBS 2026 Release · 1966–2025

Green Heron In Eastern Tallgrass Prairie

All regionsEastern Tallgrass PrairieWetland birds

Green Heron in Eastern Tallgrass Prairie has fallen sharply: down 51% on the route-weighted index since 1968.

-51%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 →
243Routes 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 →

long arc declinecomputed 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 →

Green Heron has fallen sharply in Eastern Tallgrass Prairie: down 51% on the route-weighted index since 1968.

Green Heron In Eastern Tallgrass Prairie Population Forecast

If the recent trend holds, Green Heron in Eastern Tallgrass Prairie is projected to fall about 30% by 2030 — from 0.24 in 2025 to a central estimate of 0.17 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±12.9%, with 100% of held-out values landing inside the 95% band.

-30%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 →
0.17Projected 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 →
0.00–0.3395% 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 →
±12.9%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 Eastern Tallgrass Prairie is projected to fall about 30% by 2030 — from 0.24 in 2025 to a central estimate of 0.17 (95% range 0.00–0.33). A 5-year backtest shows a typical error of ±12.9%, 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 →
20260.190.020.36
20270.180.020.35
20280.180.010.34
20290.170.000.34
20300.170.000.33

Routes In Eastern Tallgrass Prairie

Routes recording Green Heron in Eastern Tallgrass Prairie.
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 →
DaileyILLINOIS52005
GaryINDIANA51995
BelleviewILLINOIS42023
SwayzeeINDIANA42025
RockinghamMISSOURI41999
StetMISSOURI41990
KentonOHIO42013
Mill CreekILLINOIS32012
MackinawILLINOIS32021
Mascoutah LkILLINOIS32018
MonticelloINDIANA32025
PortageINDIANA32004
Davis CornerIOWA32005
MoreheadKANSAS32012
Sni MillsMISSOURI31990
SticklervillMISSOURI32012
TrentonMISSOURI32001
KearneyMISSOURI32024
GildehouseMISSOURI31989
AuburnMISSOURI32024
RaymondWISCONSIN32025
PutnamILLINOIS21996
NewarkILLINOIS22016
Terre HauteILLINOIS22024
WilliamsfldILLINOIS22018

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