Swallow Fact Sheet
  • Swallows and martins probably spend more time on the wing than any other songbirds in the world. (Swifts probably fly even more than swallows, but swifts aren't technically songbirds.)
  • Swallows belong to the family Hirundinidae. (Hirundo means swallow in Latin.)
  • Authorities believe the first swallows to build nests at the San Juan Capistrano Mission arrived in 1776.
  • Swallows are among the first migrants in autumn. They gather on wires and bare branches, usually in wetlands or near lakes and rivers. At night many roost in reeds in marshes. In medieval Europe, people believed swallows burrowed into the oozy muck of marshes for the winter. How might that idea have started?
  • Many baby and parent swallows learn each other's voices and stay together over migration. This is one reason why parent birds are so much better at raising their babies than even the most knowledgeable rehabbers.

Listen to the Cliff Swallows!


  • The Cliff Swallow makes nests of mud pellets, but shapes it like a hollow gourd with a hole for the parents to enter and the babies to look out. The Cliff Swallow is the famous "Swallow of Capistrano." It's also sometimes called the "Republican Swallow." This has nothing to do with politics; Cliff Swallows nest in little communities which reminded an early ornithologist of little republics.
  • The Barn Swallow may be the fastest swallow. It's been clocked flying 46 m.p.h. The Barn Swallow is the only North American swallow with a deeply forked tail. It's about 5 to 7 inches long, and weighs 17 to 19.8 grams, or 3/4 ounce.
  • The oldest American Barn Swallow we know about lived to be 8 years 1 month, but one European Barn Swallow (the same species) lived to be 16 years old.
  • Barn Swallows build their nests out of mud. The mud becomes shaped like pellets as the swallows pick it up and carry it in their mouths, and if you look closely at a swallow nest you'll see many of the individual mud pellets that make the nest. The nest is heavy, made from a lot of mud, and can be over a foot tall to hold it securely in place on a barn rafter, bridge, or other surface. The open cup on the top of the mass of mud is lined with feathers, horse hair, and other soft items.
  • The Barn Swallow follows the 48 degree isotherm. (Why do you think swallows need temperatures to be ten degrees warmer than robins do to return?)
  • Tree Swallows have the longest intestines of any swallow, allowing them to digest berries and other plant material.
  • Tree Swallows also are good at finding abandoned woodpecker holes and other small cavities for shelter during cold nights. That is why they are usually first to arrive in spring, and why they can live so far north. Tree Swallows have a snow-white underside and green- or blue-iridescent back. They weigh about 16.4 to 22.2 grams, or 1/2 to 3/4 ounce, and are 5 to 6 inches long. The oldest Tree Swallow that was banded and later recaptured was 12 years 1 month old.
  • Violet-green Swallows are closely related to Tree Swallows, and migrate early, often in the company of Tree Swallows. Violet-green Swallows live in the western states and provinces, and nest all the way up into Alaska and the Yukon, as Tree Swallows do. They even look like fancy Tree Swallows.The pure white of their undersides reaches up on the sides so their flanks are very white-the white areas almost meet on their rump. They're about 5 inches long. The oldest known Violet-green Swallow lived 6 years 10 months. Violet-green Swallows nest on the lodge and buildings around Old Faithful, the popular geyser in Yellowstone National Park, so millions of people have seen this beautiful bird, but many probably didn't even realize it!
  • The Purple Martin is the biggest swallow in North America, and the only swallow with an all-black, or dark purple, underside. It's 7 1/4 to 8 1/2 inches long, and weighs about 2 ounces. Martins once nested in huge colonies, but their numbers have dropped dramatically. They nest in natural cavities, gourds hollowed out for them by people, and martin houses built by people. The oldest Purple Martin to be banded and later recaptured was 13 years and 9 months old.
  • The Bank Swallow is the smallest North American swallow. It has a band across its chest like the slot of a piggy bank. It's 4 1/2 to 5 1/2 inches long, and weighs 13 to 16 grams, or 1/2 ounce. Bank Swallows burrow to build their nests in sand and gravel banks along rivers, gravel pits, highway embankments, and other places where they can burrow into soft soil or sand. They use their beak to dig, and as they get deeper and deeper into the hole, they kick out the dirt with their feet. They nest in big colonies, sometimes with hundreds of birds. The oldest Bank Swallow to be banded and recaptured was 8 years old.
  • Rough-winged Swallows look like miniature female martins-brown backs, a dusky brown throat and sides, and white belly. Rough-wings nest in banks like Bank Swallows, only usually in isolated pairs rather than in a big community. Their burrows are usually 9 to 28 inches long, but some have been found to be as long as 6 feet inside!
  • The Cave Swallow once lived only from Mexico south, coming into the U.S. to nest at Carlesbad Caverns in New Mexico. Now the northern Mexico population is increasing, and birdwatchers are seeing more and more Cave Swallows in Texas, Arizona, New Mexico, Florida, and north to Nebraska and all the way up the Atlantic coast to Nova Scotia. Birders often look for them in the culverts that drain roads. Do these swallows think culverts look like caves? Could this be why they're increasing? The oldest known Cave Swallow lived to be 7 years old.