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

Green-tailed Towhee In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsGeneralists

Green-tailed Towhee in Sonoran and Mojave Deserts has surged: up 106% on the route-weighted index since 1980.

+106%Since 1980TrendPercent 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 →
6Routes 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 →
19YearsYears 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 →

Green-tailed Towhee has surged in Sonoran and Mojave Deserts: up 106% on the route-weighted index since 1980.

Green-tailed Towhee In Sonoran and Mojave Deserts Population Forecast

If the recent trend holds, Green-tailed Towhee in Sonoran and Mojave Deserts is projected to fall about 23% by 2028 — from 0.13 in 2023 to a central estimate of 0.10 (95% range 0.01–0.20). A 5-year backtest shows a typical error of ±112.9%, with 100% of held-out values landing inside the 95% band.

-23%Change by 2028TrendPercent 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 →
0.10Projected 2028 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.01–0.2095% 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 →
±112.9%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, Green-tailed Towhee in Sonoran and Mojave Deserts is projected to fall about 23% by 2028 — from 0.13 in 2023 to a central estimate of 0.10 (95% range 0.01–0.20). A 5-year backtest shows a typical error of ±112.9%, with 100% of held-out values landing inside the 95% band.19732028
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 →
20240.100.000.19
20250.100.000.20
20260.100.000.20
20270.100.000.20
20280.100.010.20

Routes In Sonoran and Mojave Deserts

Routes recording Green-tailed 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 →
Lone PineCALIFORNIA42023
Val Of FireNEVADA22011
Eureka ValCALIFORNIA11995
Kelso ValleyCALIFORNIA12021
Joshua TreeCALIFORNIA11980
Jean LakeNEVADA12001

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