BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Great Blue Heron In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauWetland birds

Great Blue Heron in Southern Rockies / Colorado Plateau has surged: up 480% on the route-weighted index since 1972.

+480%Since 1972TrendPercent 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 →
107Routes 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 →
51YearsYears 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 Southern Rockies / Colorado Plateau: up 480% on the route-weighted index since 1972.

Great Blue Heron In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Great Blue Heron in Southern Rockies / Colorado Plateau is projected to rise about 42% by 2029 — from 0.26 in 2024 to a central estimate of 0.36 (95% range 0.18–0.55). A 5-year backtest shows a typical error of ±76.2%, with 60% of held-out values landing inside the 95% band.

+42%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 →
0.36Projected 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 →
0.18–0.5595% 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 →
±76.2%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 Southern Rockies / Colorado Plateau is projected to rise about 42% by 2029 — from 0.26 in 2024 to a central estimate of 0.36 (95% range 0.18–0.55). A 5-year backtest shows a typical error of ±76.2%, with 60% 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 →
20250.340.160.53
20260.350.160.54
20270.350.170.54
20280.360.170.55
20290.360.180.55

Routes In Southern Rockies / Colorado Plateau

Routes recording Great Blue Heron in Southern Rockies / Colorado Plateau.
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 →
BufordCOLORADO112023
CokedaleCOLORADO52024
Cochetopa PassCOLORADO52022
WaldenCOLORADO42019
CortezCOLORADO42007
Stillwater Pass 2COLORADO42016
JensenUTAH42011
NotomUTAH42024
KamasUTAH42024
YampaCOLORADO22018
HarmonyCOLORADO22019
AspenCOLORADO22024
Cheesman LkCOLORADO22016
MoffatCOLORADO22023
Lost LakeCOLORADO22005
CastletonCOLORADO22024
DoylevilleCOLORADO22024
GuffeyCOLORADO22023
Rio Grnds RsCOLORADO22024
Cortez 2COLORADO22016
Bluewater LakeNEW-MEXICO22007
Cerro VerdeNEW-MEXICO22016
Navajo LakeUTAH22009
Cane Spr DesUTAH21994
HatchUTAH22003

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