Soaring Duo

Two Galapagos Swallow Tailed Gulls glide in the sky above the R/V Atlantis during a 2010 expedition. The birds, which are the only fully nocturnal gulls and seabirds in the world, would flock around the ship at night to feed. The gulls prey on squid and small fish that migrate from the ocean twilight zone to the surface at night to feed on plankton. (Photo by Mark Spear, Woods Hole Oceanographic Institution)