Vesper Sparrow
Vesper Sparrow has held roughly steady: up 2% on the route-weighted index since 1968.
About the Vesper Sparrow
The Vesper Sparrow (Pooecetes gramineus) is a North American member of the New World Sparrows (Passerellidae). In this analysis it is grouped with the grassland birds.
- Size
- 4.5–7.5 in long (12–19 cm) — a small songbird (typical for the family)
- Habitat
- Open grasslands, prairie, pasture and hayfields.
- Diet
- Seeds and insects gathered from grasses and the ground.
- Range
- Recorded on 1,929 Breeding Bird Survey routes across 40 states, most concentrated in the Eastern Tallgrass Prairie.
- Family
- Passerellidae · Grassland birds
Notable Vesper Sparrow Trends
No notable trend signals for Vesper Sparrow. See the full index history below.
Vesper Sparrow Population Forecast
If the recent trend holds, Vesper Sparrow is projected to stay roughly flat through 2029, near 3.6 (95% range 2.6–4.7). A 5-year backtest shows a typical error of ±13%, with 100% of held-out values landing inside the 95% band.
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 3.6 | 2.5 | 4.7 |
| 2026 | 3.6 | 2.5 | 4.7 |
| 2027 | 3.6 | 2.5 | 4.7 |
| 2028 | 3.6 | 2.5 | 4.7 |
| 2029 | 3.6 | 2.6 | 4.7 |
Where the Vesper Sparrow Is Detected
BBS routes recording Vesper Sparrow, sized by most recent count.
Vesper Sparrow Population Trend by State
| Arizona | -43% | 1970 | 25 |
| California | +638% | 1972 | 41 |
| Colorado | 19× | 1970 | 124 |
| Connecticut | insufficient data | n/a | 1 |
| Delaware | -81% | 1968 | 14 |
| Idaho | +323% | 1970 | 50 |
| Illinois | -44% | 1968 | 86 |
| Indiana | -88% | 1968 | 58 |
| Iowa | -65% | 1969 | 38 |
| Kansas | -20% | 1975 | 15 |
| Kentucky | insufficient data | n/a | 7 |
| Maine | -99% | 1968 | 31 |
| Maryland | -98% | 1968 | 50 |
| Massachusetts | -79% | 1968 | 9 |
| Michigan | -92% | 1968 | 98 |
| Minnesota | -48% | 1969 | 70 |
| Missouri | -73% | 1971 | 23 |
| Montana | +70% | 1970 | 105 |
| Nebraska | +119% | 1970 | 50 |
| Nevada | +202% | 1971 | 35 |
| New Hampshire | -86% | 1968 | 20 |
| New Jersey | -67% | 1968 | 11 |
| New Mexico | +437% | 1973 | 42 |
| New York | -87% | 1968 | 93 |
| North Carolina | insufficient data | n/a | 4 |
| North Dakota | +27% | 1969 | 51 |
| Ohio | -89% | 1968 | 73 |
| Oklahoma | insufficient data | n/a | 1 |
| Oregon | +89% | 1970 | 85 |
| Pennsylvania | -96% | 1968 | 104 |
| South Dakota | -25% | 1969 | 62 |
| Tennessee | insufficient data | n/a | 1 |
| Texas | insufficient data | n/a | 5 |
| Utah | +3% | 1970 | 94 |
| Vermont | -88% | 1969 | 18 |
| Virginia | -96% | 1968 | 26 |
| Washington | +112% | 1970 | 57 |
| West Virginia | -96% | 1968 | 24 |
| Wisconsin | -93% | 1968 | 90 |
| Wyoming | +34% | 1970 | 138 |
Vesper Sparrow Population Trend by Region
Bird Conservation Regions are the ecological unit for trends.
| Northern Pacific Rainforest | -93% | 1970 | 23 |
| Great Basin | +172% | 1970 | 212 |
| Northern Rockies | +61% | 1970 | 188 |
| Prairie Potholes | +31% | 1969 | 123 |
| Boreal Hardwood Transition | -79% | 1968 | 97 |
| Lower Great Lakes / St. Lawrence Plain | -86% | 1968 | 78 |
| Atlantic Northern Forest | -97% | 1968 | 77 |
| Sierra Nevada | +2% | 1973 | 11 |
| Southern Rockies / Colorado Plateau | +94% | 1970 | 201 |
| Badlands and Prairies | +135% | 1969 | 137 |
| Shortgrass Prairie | +526% | 1970 | 56 |
| Central Mixed Grass Prairie | +57% | 1970 | 27 |
| Eastern Tallgrass Prairie | -73% | 1968 | 215 |
| Prairie Hardwood Transition | -91% | 1968 | 149 |
| Central Hardwoods | -83% | 1968 | 28 |
| Appalachian Mountains | -97% | 1968 | 190 |
| Piedmont | -99% | 1968 | 34 |
| New England / Mid-Atlantic Coast | -97% | 1968 | 61 |
| Sierra Madre Occidental | -45% | 1970 | 11 |
| Chihuahuan Desert | -93% | 1980 | 3 |
Vesper Sparrow Conservation Status
Our route-weighted index shows it up about 2% since 1968. Grassland birds are North America's steepest-declining group, down roughly 50% since 1970 as prairie and pasture were lost.
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.