Pygmy Nuthatch
Pygmy Nuthatch has risen sharply: up 70% on the route-weighted index since 1970.
About the Pygmy Nuthatch
The Pygmy Nuthatch (Sitta pygmaea) is a North American member of the Nuthatches (Sittidae). In this analysis it is grouped with the forest birds.
- Size
- 4–7 in long (10–18 cm) — a small tree-climbing 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 271 Breeding Bird Survey routes across 12 states, most concentrated in the Southern Rockies / Colorado Plateau.
- Family
- Sittidae · Forest birds
Notable Pygmy Nuthatch Trends
Pygmy Nuthatch has risen sharply in surveyed states: up 70% on the route-weighted index since 1970.
Pygmy Nuthatch Population Forecast
If the recent trend holds, Pygmy Nuthatch is projected to rise about 51% by 2029 — from 0.15 in 2024 to a central estimate of 0.23 (95% range 0.14–0.33). A 5-year backtest shows a typical error of ±31.5%, with 80% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.23 | 0.13 | 0.32 |
| 2026 | 0.23 | 0.13 | 0.32 |
| 2027 | 0.23 | 0.14 | 0.32 |
| 2028 | 0.23 | 0.14 | 0.33 |
| 2029 | 0.23 | 0.14 | 0.33 |
Where the Pygmy Nuthatch Is Detected
BBS routes recording Pygmy Nuthatch, sized by most recent count.
Pygmy Nuthatch Population Trend by State
| Arizona | +74% | 1970 | 21 |
| California | -65% | 1970 | 80 |
| Colorado | -27% | 1971 | 42 |
| Idaho | -75% | 1989 | 6 |
| Montana | -78% | 1987 | 13 |
| Nebraska | insufficient data | n/a | 2 |
| New Mexico | +943% | 1971 | 22 |
| Oregon | +33% | 1970 | 40 |
| South Dakota | insufficient data | n/a | 5 |
| Utah | -71% | 1992 | 7 |
| Washington | +45% | 1970 | 26 |
| Wyoming | -49% | 1982 | 7 |
Pygmy Nuthatch Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Northern Pacific Rainforest | -63% | 1972 | 16 |
| Great Basin | +137% | 1971 | 51 |
| Northern Rockies | -53% | 1970 | 47 |
| Sierra Nevada | -72% | 1971 | 23 |
| Southern Rockies / Colorado Plateau | +94% | 1970 | 69 |
| Shortgrass Prairie | +360% | 1982 | 5 |
| Coastal California | -66% | 1970 | 29 |
| Sierra Madre Occidental | -0% | 1970 | 20 |
| Chihuahuan Desert | -72% | 1982 | 3 |
Pygmy Nuthatch Conservation Status
Our route-weighted index shows it up about 70% 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.