The Bank Swallow, the smallest swallow species in North America, occurs in Arizona primarily as a migrant. These compact birds, with their brown upperparts, white underparts, and distinctive dark breast band, pass through the state in spring and fall while traveling between breeding grounds farther north and wintering areas in South America. Unlike other swallow species that may nest in Arizona, Bank Swallows are not known to breed here. Their nesting habitat requires vertical banks of sand or soil where they excavate tunnels for colonies, conditions not typically present in the state’s landscape.
During migration, they are most often observed near rivers, lakes, and other bodies of water where they forage on flying insects. They can sometimes be seen in mixed flocks with Northern Rough-winged Swallows (Stelgidopteryx serripennis), Tree Swallows (Tachycineta bicolor), or Barn Swallows (Hirundo rustica). Because of their brief presence and tendency to move in flocks, sightings in Arizona can be sporadic and localized, yet they are a regular passage migrant.
