Townsend's Warbler
Townsend's Warbler has surged: up 871% on the route-weighted index since 1970.
About the Townsend's Warbler
The Townsend's Warbler (Setophaga townsendi) is a North American member of the Wood-Warblers (Parulidae). In this analysis it is grouped with the forest birds.
- Size
- 4.5–5.5 in long (11–14 cm) — a small, active 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 261 Breeding Bird Survey routes across 6 states, most concentrated in the Northern Rockies.
- Family
- Parulidae · Forest birds
Notable Townsend's Warbler Trends
Townsend's Warbler has surged in surveyed states: up 871% on the route-weighted index since 1970.
Townsend's Warbler Population Forecast
If the recent trend holds, Townsend's Warbler is projected to rise about 24% by 2029 — from 0.57 in 2024 to a central estimate of 0.71 (95% range 0.54–0.87). A 5-year backtest shows a typical error of ±24.5%, with 80% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.66 | 0.50 | 0.83 |
| 2026 | 0.67 | 0.51 | 0.84 |
| 2027 | 0.69 | 0.52 | 0.85 |
| 2028 | 0.69 | 0.53 | 0.86 |
| 2029 | 0.71 | 0.54 | 0.87 |
Where the Townsend's Warbler Is Detected
BBS routes recording Townsend's Warbler, sized by most recent count.
Townsend's Warbler Population Trend by State
| Alaska | +131% | 1982 | 72 |
| Idaho | +770% | 1972 | 26 |
| Montana | +183% | 1970 | 29 |
| Oregon | +85% | 1970 | 62 |
| Washington | +129% | 1970 | 69 |
| Wyoming | insufficient data | n/a | 3 |
Townsend's Warbler Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 4 | +49% | 1984 | 39 |
| Northern Pacific Rainforest | 15× | 1970 | 88 |
| Great Basin | +27% | 1970 | 40 |
| Northern Rockies | +219% | 1970 | 93 |
Townsend's Warbler Conservation Status
Our route-weighted index shows it up about 871% since 1970.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.