They have been in the sky circling around the vicinty of the White Oak Pavilion for the past week or so. Yesterday I watched them trying to claim and defend the boxes and other nesting cavities. They were chasing each other and making twittering sounds as they wove invisible, swooping tapestries through the air. Occasionally two would have a tussling embrace that would flutter to the ground where they would release each other. This all seemed pretty harmless as they worked it out between them who was going to nest where.
Their migration pattern according to the website All About Birds: “Medium to long-distance migrant. Most individuals migrate to Mexico and Central America during the nonbreeding season, heading as far south as Costa Rica. Some individuals spend winters in California’s Imperial Valley, the lower Colorado River Valley, and coastal California.”