Grassland Bird Species

Vesper Sparrow

The vesper sparrow has been declining rapidly for many decades and is considered regionally threatened throughout the Northeast. Where found, this sparrow is most often heard singing its clear, sweet song at twilight atop a small tree in a grassland. In the Northeast, vesper sparrows prefer dry habitats such as sandplain grasslands, blueberry barrens and coastal dunes. It is likely that this species once occupied openings created by forest fires. Since such disturbances are now very rare, these habitats have declined. Vesper sparrows thrived in New England in the 18th and 19th centuries with the expansion of Colonial agriculture. However, the species has not adapted successfully to modern agricultural practices; it will not breed in densely vegetated hayfields and pastures. They are, however, occasionally found breeding in weedy areas adjacent to large potato fields.

Life History

Vesper sparrows prefer patchier grassland habitat and usually select sites with bare ground and reduced litter. Fence posts, shrubs, and small trees are used as singing perches. They require breeding sites of at least 15 acres but prefer areas greater than 35 acres. The breeding season lasts from early May until mid-August, during which time they raise two to three broods. Therefore, early season mowing can harm nesting birds and young. Management for vesper sparrow habitat involves the maintenance of dry, native grasslands. Grassland habitats require periodic mowing or, preferably, burning, to maintain an early successional state and to reduce litter.

Reason for Decline

• Habitat loss. Loss of appropriate habitat to natural succession, land development, and intensive agriculture, appears to be the primary factor in this species' decline.
• Changes in agricultural practices. Converting native grasslands to densely vegetated fields of fast-growing legumes or cool-season grasses does not provide adequate breeding habitat. In addition, early-summer mowing destroys nesting areas for this species' long nesting season.

Map of distribution and abundance

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