BirdAnalyst
Species · Alaska · BBS 2025 Release · 1966–2024

Great Blue Heron Population Trend in Alaska

All statesWetland birds

Great Blue Heron in Alaska has collapsed: down 97% on the route-weighted index since 1973.

-97%Since 1973TrendPercent 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 →
21Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
44YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Great Blue Heron Trends in AlaskaNotable 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 →

Great Blue Heron has collapsed in Alaska: down 97% on the route-weighted index since 1973.

Great Blue Heron Population Forecast in Alaska

If the recent trend holds, Great Blue Heron in Alaska is projected to fall about 100% by 2029 — from 0.09 in 2024 to a central estimate of 0.00 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±1337.5%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–1.695% 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 →
±1337.5%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 Alaska is projected to fall about 100% by 2029 — from 0.09 in 2024 to a central estimate of 0.00 (95% range 0.00–1.6). A 5-year backtest shows a typical error of ±1337.5%, with 100% of held-out values landing inside the 95% band.19712029
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 →
20250.000.001.6
20260.000.001.6
20270.000.001.6
20280.000.001.6
20290.000.001.6

Great Blue Heron Survey Routes in Alaska

Routes recording Great Blue Heron in Alaska.
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 →
Skagway520241993
Mitkof Isle320082008
Yakutat320032003
Juneau Alt219861984
Ketchikan220221971
Zarembo220211996
Wrangell (Short)219841984
Juneau120241986
Craig120082008
Haines120231972
Hoonah120212021
Whale Pass120211998
Cordova120091995
Chichagof Is120122003
Sitka (Short)119921985
Hyder120081998
Copper River119971997
Thorne Bay 2120212021
Zimovia Strt120231988
Sitka120161993
Thorne Bay119971997

Great Blue Heron Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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