Black-throated Gray Warbler
Black-throated Gray Warbler has surged: up 115% on the route-weighted index since 1970.
About the Black-throated Gray Warbler
The Black-throated Gray Warbler (Setophaga nigrescens) 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 436 Breeding Bird Survey routes across 10 states, most concentrated in the Northern Pacific Rainforest.
- Family
- Parulidae · Forest birds
Notable Black-throated Gray Warbler Trends
Black-throated Gray Warbler has surged in surveyed states: up 115% on the route-weighted index since 1970.
Black-throated Gray Warbler Population Forecast
If the recent trend holds, Black-throated Gray Warbler is projected to rise about 36% by 2029 — from 0.27 in 2024 to a central estimate of 0.37 (95% range 0.26–0.48). A 5-year backtest shows a typical error of ±35.7%, with 40% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.36 | 0.25 | 0.47 |
| 2026 | 0.36 | 0.25 | 0.48 |
| 2027 | 0.37 | 0.26 | 0.48 |
| 2028 | 0.37 | 0.26 | 0.48 |
| 2029 | 0.37 | 0.26 | 0.48 |
Where the Black-throated Gray Warbler Is Detected
BBS routes recording Black-throated Gray Warbler, sized by most recent count.
Black-throated Gray Warbler Population Trend by State
| Arizona | +8% | 1970 | 29 |
| California | +87% | 1970 | 133 |
| Colorado | +215% | 1975 | 40 |
| Idaho | -6% | 1986 | 7 |
| Nevada | -36% | 1992 | 14 |
| New Mexico | -7% | 1970 | 22 |
| Oregon | +1% | 1970 | 72 |
| Utah | -18% | 1977 | 60 |
| Washington | -36% | 1970 | 55 |
| Wyoming | insufficient data | n/a | 4 |
Black-throated Gray Warbler Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Northern Pacific Rainforest | -32% | 1970 | 124 |
| Great Basin | -7% | 1970 | 78 |
| Northern Rockies | -25% | 1990 | 15 |
| Sierra Nevada | +311% | 1971 | 30 |
| Southern Rockies / Colorado Plateau | +0% | 1970 | 109 |
| Coastal California | +881% | 1970 | 49 |
| Sierra Madre Occidental | +15% | 1974 | 24 |
Black-throated Gray Warbler Conservation Status
Our route-weighted index shows it up about 115% 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.