Bird Sea is a term used to describe three different types of birds. PETREL (6 letters) is a type of seabird that typically has long wings and a hooked bill. TERN (4 letters) is a type of seabird that is known for its graceful flight and pointed wings. AUK (3 letters) is a type of seabird that is characterized by its short wings and webbed feet, which make it an excellent swimmer. All three of these birds are found in the ocean and are important to the marine ecosystem.