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

Bullock's Oriole In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsGeneralists

Bullock's Oriole in Sonoran and Mojave Deserts has fallen sharply: down 51% on the route-weighted index since 1970.

-51%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 →
67Routes 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 →

long arc declinecomputed 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 →

Bullock's Oriole has fallen sharply in Sonoran and Mojave Deserts: down 51% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Bullock's Oriole in Sonoran and Mojave Deserts is projected to fall about 13% by 2029 — from 0.80 in 2024 to a central estimate of 0.69 (95% range 0.05–1.3). A 5-year backtest shows a typical error of ±44.2%, with 100% of held-out values landing inside the 95% band.

-13%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 →
0.69Projected 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 →
0.05–1.395% 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 →
±44.2%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, Bullock's Oriole in Sonoran and Mojave Deserts is projected to fall about 13% by 2029 — from 0.80 in 2024 to a central estimate of 0.69 (95% range 0.05–1.3). A 5-year backtest shows a typical error of ±44.2%, 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 →
20250.730.091.4
20260.720.081.4
20270.710.071.4
20280.700.061.3
20290.690.051.3

Routes In Sonoran and Mojave Deserts

Routes recording Bullock's Oriole 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 2ARIZONA122018
GlamisCALIFORNIA91995
Ajo 2ARIZONA72019
Bates WellARIZONA62023
Lone PineCALIFORNIA62024
Casa GrandeARIZONA52021
Palo VerdeARIZONA42013
Palo Verde 2ARIZONA42024
OnyxCALIFORNIA42015
CimaCALIFORNIA42021
Willow Springs 2CALIFORNIA42018
QuartzsiteARIZONA32017
FlorenceARIZONA31973
WickenburgARIZONA32019
Red Rock 2ARIZONA32024
Kelso ValleyCALIFORNIA32024
Joshua TreeCALIFORNIA32000
WikieupARIZONA22019
VicksburgARIZONA21989
New RiverARIZONA22016
AjoARIZONA22000
Alamo Res.ARIZONA22019
Cabeza PrietARIZONA22024
Cactus ForestARIZONA22013
Organ PipeARIZONA22023

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