American Tree Sparrow
American Tree Sparrow has surged: up 93× on the route-weighted index since 1977.
About the American Tree Sparrow
The American Tree Sparrow (Spizelloides arborea) 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 73 Breeding Bird Survey routes across 1 state, most concentrated in the BCR 4.
- Family
- Passerellidae · Forest birds
Notable American Tree Sparrow Trends
No notable trend signals for American Tree Sparrow. See the full index history below.
American Tree Sparrow Population Forecast
If the recent trend holds, American Tree Sparrow is projected to rise about 15% by 2029 — from 0.22 in 2024 to a central estimate of 0.26 (95% range 0.12–0.40). A 5-year backtest shows a typical error of ±16.2%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.24 | 0.10 | 0.39 |
| 2026 | 0.25 | 0.10 | 0.39 |
| 2027 | 0.25 | 0.11 | 0.39 |
| 2028 | 0.25 | 0.11 | 0.40 |
| 2029 | 0.26 | 0.12 | 0.40 |
Where the American Tree Sparrow Is Detected
BBS routes recording American Tree Sparrow, sized by most recent count.
American Tree Sparrow Population Trend by State
| Alaska | +518% | 1977 | 73 |
American Tree Sparrow Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| BCR 2 | +49% | 1987 | 19 |
| BCR 3 | +347% | 1996 | 4 |
| BCR 4 | +227% | 1977 | 44 |
| Northern Pacific Rainforest | -92% | 1985 | 6 |
American Tree Sparrow Conservation Status
Our route-weighted index shows it up about 9224% since 1977.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.