arctic bird coast coastal migration seabirds tern terns adaptable appearance black-capped bright crest crested crested-tern diver diving fish-catcher freshwater greater-crested-tern perched perching plunge-diving river riverside saltwater seabird sunlight sunshine swift-tern thalasseus-bergii water-bird yellow-billed avian beak bill feather nature ocean plumage sea tern shore water care feeding home marthlet martin nest swallow birding birds closeup India macro Mangalore migrant migrating migratory monsoon Sterna fuscata Tannirbavi The Sooty Tern abstract background clouds concept Gulf of Mexico sea gull sun wallpaper air airborne beach beaches feathers flight flying Laridae natural peace seagulls sky