BirdAnalyst
Species · California · BBS 2025 Release · 1966–2024

Green-tailed Towhee Population Trend in California

All statesGeneralists

Green-tailed Towhee in California has surged: up 110% on the route-weighted index since 1970.

+110%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 →
85Routes In StateSurvey 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 Green-tailed Towhee Trends in CaliforniaNotable 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 California: up 110% on the route-weighted index since 1970.

Green-tailed Towhee Population Forecast in California

If the recent trend holds, Green-tailed Towhee in California is projected to rise about 14% by 2029 — from 2.5 in 2024 to a central estimate of 2.9 (95% range 1.8–3.9). A 5-year backtest shows a typical error of ±14%, with 100% of held-out values landing inside the 95% band.

+14%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 →
2.9Projected 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 →
1.8–3.995% 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 →
±14%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 California is projected to rise about 14% by 2029 — from 2.5 in 2024 to a central estimate of 2.9 (95% range 1.8–3.9). A 5-year backtest shows a typical error of ±14%, 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 →
20252.81.83.9
20262.81.83.9
20272.91.83.9
20282.91.83.9
20292.91.83.9

Green-tailed Towhee Survey Routes in California

Routes recording Green-tailed Towhee in California.
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 →
Bodie8420241982
Big Bear4019861969
Crowley Lake3920241972
Valyermo3420191970
Deep Springs2720221972
Little Truckee2320231997
Pine Mountain2220171997
Eagle Lake2020241969
Last Chance1920191993
Chilcoot1820241998
Benton1320241973
Westville1220241971
Dardanelle1120191972
Johnsville1120241975
South Fork Mtn1120222000
Ship Mtn.1020161995
Crestview1020241997
Tionesta820211997
Medicine Mtn.720152000
Woodfords620241973
Macdoel619931976
Bridgeport619771973
Mt Shasta620191978
Cottage Spgs519681968
Green Valley520221970

Green-tailed Towhee Population Trend in Other States

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