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

Blue Grosbeak In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsGeneralists

Blue Grosbeak in Sonoran and Mojave Deserts has declined: down 45% on the route-weighted index since 1970.

-45%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 →
31Routes 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 Blue Grosbeak in Sonoran and Mojave Deserts. See the full index history below.

Forecast

If the recent trend holds, Blue Grosbeak in Sonoran and Mojave Deserts is projected to rise about 49% by 2029 — from 0.27 in 2024 to a central estimate of 0.40 (95% range 0.00–0.81). A 5-year backtest shows a typical error of ±48.9%, with 100% of held-out values landing inside the 95% band.

+49%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 →
0.40Projected 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 →
0.00–0.8195% 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 →
±48.9%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, Blue Grosbeak in Sonoran and Mojave Deserts is projected to rise about 49% by 2029 — from 0.27 in 2024 to a central estimate of 0.40 (95% range 0.00–0.81). A 5-year backtest shows a typical error of ±48.9%, 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 →
20250.390.000.80
20260.400.000.80
20270.400.000.80
20280.400.000.81
20290.400.000.81

Routes In Sonoran and Mojave Deserts

Routes recording Blue Grosbeak 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 →
DatelandARIZONA42016
Cutter 2ARIZONA42018
OnyxCALIFORNIA42001
Havasu LakeCALIFORNIA31973
Ash MeadowsNEVADA32024
Cibola LakeARIZONA22002
Calif CityCALIFORNIA21980
GlamisCALIFORNIA21977
NilandCALIFORNIA22021
Lone PineCALIFORNIA22024
Kelso ValleyCALIFORNIA22024
Jean LakeNEVADA22010
FlorenceARIZONA11988
LagunaARIZONA12023
Alamo Res.ARIZONA12019
Palo VerdeARIZONA12012
ArabyARIZONA12022
Red RockARIZONA12012
Casa GrandeARIZONA12017
Cactus ForestARIZONA12024
Palo Verde 2ARIZONA12021
Red Rock 2ARIZONA12015
Haiwee ResCALIFORNIA11992
Palo VerdeCALIFORNIA12023
Anza BorregoCALIFORNIA12016

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