Fun Facts About Tree Swallows

• Migrating and wintering Tree Swallows can form enormous flocks numbering in the hundreds of thousands. They gather about an hour before sunset and form a dense cloud above a roost site (such as a cattail marsh or grove of small trees), swirling around like a living tornado. With each pass, more birds drop down until they are all settled on the roost.
• Tree Swallows winter farther north than any other American swallows and return to their nesting grounds long before other swallows come back.
• They can eat plant foods as well as their normal insect prey, which helps them survive the cold snaps and wintry weather of early spring.
• The Tree Swallow—which is most often seen in open, treeless areas—gets its name from its habit of nesting in tree cavities. They also take readily to nest boxes.
• Tree Swallows have helped researchers make major advances in several branches of ecology, and they are among the best-studied bird species in North America. Still, we know little about their lives during migration and winter.
• The oldest Tree Swallow on record was at least 12 years, 1 month old when it was recaptured and released during banding operations in Ontario in 1998.