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

Western Kingbird In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsAerial insectivores

Western Kingbird in Sonoran and Mojave Deserts has fallen sharply: down 59% on the route-weighted index since 1970.

-59%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 →
83Routes 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 →

Western Kingbird has fallen sharply in Sonoran and Mojave Deserts: down 59% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Western Kingbird in Sonoran and Mojave Deserts is projected to rise about 80% by 2029 — from 2.6 in 2024 to a central estimate of 4.7 (95% range 1.4–8.1). A 5-year backtest shows a typical error of ±105.5%, with 40% of held-out values landing inside the 95% band.

+80%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 →
4.7Projected 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 →
1.4–8.195% 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 →
±105.5%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, Western Kingbird in Sonoran and Mojave Deserts is projected to rise about 80% by 2029 — from 2.6 in 2024 to a central estimate of 4.7 (95% range 1.4–8.1). A 5-year backtest shows a typical error of ±105.5%, with 40% 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 →
20254.91.68.3
20264.91.58.3
20274.81.58.2
20284.81.48.2
20294.71.48.1

Routes In Sonoran and Mojave Deserts

Routes recording Western Kingbird 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 →
Imperial DamCALIFORNIA252010
Palo VerdeCALIFORNIA222024
WildroseCALIFORNIA211994
BlytheCALIFORNIA202003
Cibola LakeARIZONA182021
OnyxCALIFORNIA182015
Alamo RiverCALIFORNIA162018
AlamoNEVADA151973
Palo VerdeARIZONA142013
Palo Verde 2ARIZONA132024
BrawleyCALIFORNIA122012
Parker DamCALIFORNIA112007
GlamisCALIFORNIA102018
NilandCALIFORNIA92024
Hope 2ARIZONA82019
Willow SpgsCALIFORNIA81981
NelsonNEVADA82024
PearblossomCALIFORNIA72024
Cactus ForestARIZONA62024
Haiwee ResCALIFORNIA62005
VicksburgARIZONA51989
Cutter 2ARIZONA52018
Red Rock 2ARIZONA52023
CadizCALIFORNIA51991
LenwoodCALIFORNIA52012

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