There are six species of migratory birds in the Calcariidae family. The Snow Bunting (Plectrophenax nivalis) and Lapland Longspur (Calcarius lapponicus) are found in both North America and Eurasia. The other four species in this family are found only in North America.

Birds in the Calcariidae family usually have brown, gray, and white feathers that help them blend into their surroundings. They live in open habitats such as tundra, grasslands, and coastal areas. They eat mostly seeds and grasses, but also eat insects, especially during the breeding season when they need extra protein for their chicks.

Longspurs get their name from the long claw on their hind toe, which helps them walk and move through grassy and tundra habitats. These birds were once classified as members of the Emberizidae family, but DNA studies showed that they are not closely related.