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

Abert's Towhee In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsArid-land birds

Abert's Towhee in Sonoran and Mojave Deserts has surged: up 209% on the route-weighted index since 1971.

+209%Since 1971TrendPercent 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 →
55YearsYears 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 →

Abert's Towhee has surged in Sonoran and Mojave Deserts: up 209% on the route-weighted index since 1971.

Abert's Towhee In Sonoran and Mojave Deserts Population Forecast

If the recent trend holds, Abert's Towhee in Sonoran and Mojave Deserts is projected to rise about 139% by 2029 — from 0.70 in 2024 to a central estimate of 1.7 (95% range 0.67–2.7). A 5-year backtest shows a typical error of ±119.4%, with 40% of held-out values landing inside the 95% band.

+139%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 →
1.7Projected 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 →
0.67–2.795% 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 →
±119.4%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, Abert's Towhee in Sonoran and Mojave Deserts is projected to rise about 139% by 2029 — from 0.70 in 2024 to a central estimate of 1.7 (95% range 0.67–2.7). A 5-year backtest shows a typical error of ±119.4%, 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 →
20251.60.602.6
20261.60.622.6
20271.60.642.6
20281.70.652.7
20291.70.672.7

Routes In Sonoran and Mojave Deserts

Routes recording Abert's Towhee 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 →
Casa GrandeARIZONA102023
NilandCALIFORNIA102024
BrawleyCALIFORNIA92001
Parker DamCALIFORNIA62007
FlorenceARIZONA51988
Cactus ForestARIZONA52024
LagunaARIZONA42019
Palo VerdeARIZONA42013
ArabyARIZONA42023
WickenburgARIZONA42023
Coachella CnCALIFORNIA42000
BlytheCALIFORNIA41979
New RiverARIZONA32016
DatelandARIZONA32021
RivieraARIZONA32021
Palo Verde 2ARIZONA32024
Imperial DamCALIFORNIA32006
Alamo Res.ARIZONA22023
Cibola LakeARIZONA22024
Cutter 2ARIZONA22017
GlamisCALIFORNIA22017
Havasu LakeCALIFORNIA22003
CoolidgeARIZONA11985
Red RockARIZONA12006
Red Rock 2ARIZONA12024

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