BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Great Blue Heron In Northern Rockies

All regionsNorthern RockiesWetland birds

Great Blue Heron in Northern Rockies has edged down: down 24% on the route-weighted index since 1970.

-24%Since 1970TrendPercent 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 →
144Routes 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 →
56YearsYears 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 Northern Rockies. See the full index history below.

Forecast

If the recent trend holds, Great Blue Heron in Northern Rockies is projected to fall about 48% by 2029 — from 0.31 in 2024 to a central estimate of 0.16 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±22.3%, with 100% of held-out values landing inside the 95% band.

-48%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 →
0.16Projected 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 →
0.00–1.495% 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 →
±22.3%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 Northern Rockies is projected to fall about 48% by 2029 — from 0.31 in 2024 to a central estimate of 0.16 (95% range 0.00–1.4). A 5-year backtest shows a typical error of ±22.3%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.230.001.5
20260.210.001.4
20270.200.001.4
20280.180.001.4
20290.160.001.4

Routes In Northern Rockies

Routes recording Great Blue Heron in Northern Rockies.
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 →
Green RiverWYOMING131984
DanielWYOMING61988
YellowstoneWYOMING62022
CodyWYOMING52024
BasinWYOMING52017
Pablo Res.MONTANA42024
East Glacier ParkMONTANA42024
RandolphUTAH42022
OttoWYOMING42008
Big SandyWYOMING42008
Browns ParkCOLORADO32015
NaplesIDAHO32024
LaurelMONTANA32022
Church HillMONTANA32024
AnchorWYOMING32016
RawlinsWYOMING32005
MoranWYOMING32016
NezperceIDAHO22007
Baldy MountainIDAHO22015
CabartonIDAHO22023
ArleeMONTANA22024
Willow CreekMONTANA21981
Thompson RivMONTANA21995
Painted RockMONTANA22016
NoxonMONTANA21998

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