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

Double-crested Cormorant In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsWetland birds

Double-crested Cormorant in Sonoran and Mojave Deserts has declined: down 34% on the route-weighted index since 1979.

-34%Since 1979TrendPercent 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 →
16Routes 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 →
38YearsYears 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 Double-crested Cormorant in Sonoran and Mojave Deserts. See the full index history below.

Forecast

If the recent trend holds, Double-crested Cormorant in Sonoran and Mojave Deserts is projected to rise about 31× by 2029 — from 0.17 in 2024 to a central estimate of 5.2 (95% range 0.00–12). A 5-year backtest shows a typical error of ±8013.8%, with 60% of held-out values landing inside the 95% band.

31×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 →
5.2Projected 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 →
0.00–1295% 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 →
±8013.8%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, Double-crested Cormorant in Sonoran and Mojave Deserts is projected to rise about 31× by 2029 — from 0.17 in 2024 to a central estimate of 5.2 (95% range 0.00–12). A 5-year backtest shows a typical error of ±8013.8%, with 60% of held-out values landing inside the 95% band.19772029
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 →
20254.70.0012
20264.80.0012
20274.90.0012
20285.00.0012
20295.20.0012

Routes In Sonoran and Mojave Deserts

Routes recording Double-crested Cormorant 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 →
Cutter 2ARIZONA1552018
Alamo Res.ARIZONA162016
Palo VerdeARIZONA92012
Willow Beach 2ARIZONA72017
Red RockARIZONA52001
New RiverARIZONA42005
NilandCALIFORNIA42024
ArabyARIZONA22011
Imperial DamCALIFORNIA22010
BrawleyCALIFORNIA22012
Ash MeadowsNEVADA22015
LagunaARIZONA12018
Casa GrandeARIZONA11995
Palo Verde 2ARIZONA12024
Palo VerdeCALIFORNIA12010
Coachella CnCALIFORNIA11988

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