Tree Swallows
Swallows are a familiar sight across Arizona, especially during spring and summer migration, when large numbers pass through the state, and in the breeding season, when several species nest locally. These agile aerial insectivores are best known for their long, pointed wings, forked or slightly notched tails, and constant flight while feeding on flying insects over open areas, wetlands, lakes, and grasslands.
Among the most common in Arizona is the Barn Swallow (Hirundo rustica), easily recognized by its deeply forked tail and rusty underparts. Tree Swallows (Tachycineta bicolor) migrate through the state in large numbers, with their iridescent blue backs and clean white bellies. Violet-green Swallows (Tachycineta thalassina) are widespread in forested regions, especially in the Sky Islands, where they nest in cavities and show greenish backs with violet rumps and white wrapping around the sides of the head.
Northern Rough-winged Swallows (Stelgidopteryx serripennis) are summer residents, nesting in burrows or crevices near water and identifiable by their plain brown plumage and dusky throat. Bank Swallows (Riparia riparia) are less common but occur in colonies along riverbanks and sandy cuts during migration. Cliff Swallows (Petrochelidon pyrrhonota) are locally abundant, nesting in large gourd-shaped mud nests under bridges, cliffs, and buildings, often in very large colonies. Purple Martins (Progne subis), North America’s largest swallow, also breed in parts of southern and southeastern Arizona, where they nest in cavities in sycamores and saguaro cacti.