The Savannah Sparrow (Passerculus sandwichensis) is native to North America. It is widespread across the continent, with its geographical distribution stretching from the tundra of northern Canada and Alaska down to the central and northern United States. It is also found in localized areas in Mexico during the winter migration.

The Savannah Sparrow typically inhabits open areas with low vegetation, such as grasslands, fields, and marshes. Its preferred environments include tundra, coastal grasslands, agricultural fields, meadows, prairies, and pastures. The climate in these areas ranges from temperate to cold in the northern parts of its range.

This species occupies a niche as a ground-nesting insectivore and granivore. During breeding season, it primarily feeds on insects and arthropods, providing pest control. In winter, its diet shifts more towards seeds and grains. It plays a significant role in the ecosystem by affecting plant seed dispersal and maintaining insect populations in check. Regional adaptations may occur, with variations in diet and habitat use depending on local environmental conditions.