BirdAnalyst
Species · BCR 33 · BBS 2025 Release · 1966–2024

Great Blue Heron In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsWetland birds

Great Blue Heron in Sonoran and Mojave Deserts has surged: up 121% on the route-weighted index since 1973.

+121%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 →
29Routes 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 →
53YearsYears 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 Sonoran and Mojave Deserts: up 121% on the route-weighted index since 1973.

Great Blue Heron In Sonoran and Mojave Deserts Population Forecast

If the recent trend holds, Great Blue Heron in Sonoran and Mojave Deserts is projected to fall about 27% by 2029 — from 0.47 in 2024 to a central estimate of 0.34 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±75%, with 100% of held-out values landing inside the 95% band.

-27%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 →
0.34Projected 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 →
0.00–1.395% 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 →
±75%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 Sonoran and Mojave Deserts is projected to fall about 27% by 2029 — from 0.47 in 2024 to a central estimate of 0.34 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±75%, 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 →
20250.360.001.4
20260.360.001.4
20270.350.001.4
20280.350.001.4
20290.340.001.3

Routes In Sonoran and Mojave Deserts

Routes recording Great Blue Heron in Sonoran and Mojave Deserts.
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 →
Palo Verde 2ARIZONA102024
Palo VerdeARIZONA62013
NilandCALIFORNIA42024
Alamo Res.ARIZONA32016
IvanpahCALIFORNIA32007
Cutter 2ARIZONA22018
Coachella CnCALIFORNIA22013
BlytheCALIFORNIA22003
Ash MeadowsNEVADA22016
New RiverARIZONA12000
FlorenceARIZONA11970
LagunaARIZONA12023
CoolidgeARIZONA11977
RivieraARIZONA12023
Cibola LakeARIZONA12018
ArabyARIZONA12022
Casa GrandeARIZONA12023
Willow Beach 2ARIZONA12017
OnyxCALIFORNIA11992
Calif CityCALIFORNIA11996
Parker DamCALIFORNIA12007
Palo VerdeCALIFORNIA12023
DarwinCALIFORNIA12012
Alamo RiverCALIFORNIA11991
Imperial DamCALIFORNIA12010

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