Pacific Wren
Pacific Wren has surged: up 488% on the route-weighted index since 1970.
About the Pacific Wren
The Pacific Wren (Troglodytes pacificus) is a North American member of the Wrens (Troglodytidae). In this analysis it is grouped with the forest birds.
- Size
- 4–8.5 in long (10–22 cm) — a small, energetic 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 287 Breeding Bird Survey routes across 8 states, most concentrated in the Northern Pacific Rainforest.
- Family
- Troglodytidae · Forest birds
Notable Pacific Wren Trends
Pacific Wren has surged in surveyed states: up 488% on the route-weighted index since 1970.
Pacific Wren Population Forecast
If the recent trend holds, Pacific Wren is projected to rise about 30% by 2029 — from 0.61 in 2024 to a central estimate of 0.80 (95% range 0.50–1.1). A 5-year backtest shows a typical error of ±49.7%, with 60% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.76 | 0.46 | 1.1 |
| 2026 | 0.77 | 0.47 | 1.1 |
| 2027 | 0.78 | 0.48 | 1.1 |
| 2028 | 0.79 | 0.49 | 1.1 |
| 2029 | 0.80 | 0.50 | 1.1 |
Where the Pacific Wren Is Detected
BBS routes recording Pacific Wren, sized by most recent count.
Pacific Wren Population Trend by State
| Alaska | -15% | 1974 | 37 |
| California | +353% | 1970 | 63 |
| Idaho | +583% | 1976 | 18 |
| Montana | +463% | 1971 | 23 |
| Nevada | insufficient data | n/a | 1 |
| Oregon | +124% | 1970 | 71 |
| South Dakota | insufficient data | n/a | 1 |
| Washington | +12% | 1970 | 73 |
Pacific Wren Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 2 | -51% | 1985 | 3 |
| Northern Pacific Rainforest | +161% | 1970 | 142 |
| Great Basin | +129% | 1970 | 31 |
| Northern Rockies | +606% | 1970 | 73 |
| Sierra Nevada | +266% | 1974 | 19 |
| Coastal California | 15× | 1976 | 12 |
Pacific Wren Conservation Status
Our route-weighted index shows it up about 488% 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.