Migrating from South Africa, a flock of Sand Martins feed on mayflies along the river banks of Hungary. The insects provide an abundance of food for the large populations of birds nesting near the water. In this scene from EARTHFLIGHT: Europe, Sand Martins glide just above the water’s surface, catching these aquatic insects with impressive accuracy. Watch a scene from EARTHFLIGHT: Europe which airs Wednesday, September 18 at 8PM ET (check local listings). (Restricted to U.S. and Territories.)