BirdAnalyst
Species · BBS 2026 Release · 1966–2025

Green-tailed Towhee Population Analysis

PasserellidaeForest birdsPipilo chlorurus

Green-tailed Towhee has surged: up 434% on the route-weighted index since 1970.

+434%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 →
525RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
57Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Green-tailed Towhee

The Green-tailed Towhee (Pipilo chlorurus) is a North American member of the New World Sparrows (Passerellidae). In this analysis it is grouped with the forest birds.

Size
4.5–7.5 in long (12–19 cm) — a small songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 525 Breeding Bird Survey routes across 11 states, most concentrated in the Southern Rockies / Colorado Plateau.
Family
Passerellidae · Forest birds

Notable Green-tailed Towhee TrendsNotable 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 surveyed states: up 434% on the route-weighted index since 1970.

Green-tailed Towhee Population Forecast

If the recent trend holds, Green-tailed Towhee is projected to rise about 11% by 2030 — from 1.1 in 2025 to a central estimate of 1.2 (95% range 0.91–1.4). A 5-year backtest shows a typical error of ±34.2%, with 20% of held-out values landing inside the 95% band.

+11%Change by 2030TrendPercent 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 →
1.2Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.91–1.495% 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 →
±34.2%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, Green-tailed Towhee is projected to rise about 11% by 2030 — from 1.1 in 2025 to a central estimate of 1.2 (95% range 0.91–1.4). A 5-year backtest shows a typical error of ±34.2%, with 20% of held-out values landing inside the 95% band.19682030
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 →
20261.10.861.4
20271.10.871.4
20281.10.891.4
20291.20.901.4
20301.20.911.4

Where the Green-tailed Towhee Is Detected

BBS routes recording Green-tailed Towhee, sized by most recent count.

Green-tailed Towhee Population Trend by State

Green-tailed Towhee population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Arizona+627%198813
California+97%197085
Colorado+68%1970106
Idaho+233%197125
Montana-16%197022
Nevada+187%197028
New Mexico+189%197035
Oregon+68%197052
Texasinsufficient datan/a2
Utah+104%197068
Wyoming+95%197089

Green-tailed Towhee Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Green-tailed Towhee population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Pacific Rainforest-69%197417
Great Basin+200%1970116
Northern Rockies+81%1970117
Sierra Nevada+38%197036
Southern Rockies / Colorado Plateau+150%1970182
Badlands and Prairies-72%197917
Shortgrass Prairie-47%19946
Coastal California-97%197113
Sonoran and Mojave Deserts+106%19806
Sierra Madre Occidental+354%19889
Chihuahuan Desert-60%19776

Green-tailed Towhee Conservation Status

Our route-weighted index shows it up about 434% since 1970.

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.