Shearwaters are a genus of seabirds that belong to the family Procellariidae. They are known for their long and narrow wings that enable them to soar over great distances without flapping. Other synonyms for shearwaters include puffinus, petrels, and fulmars. Puffinus is a group of seabirds that includes species of shearwaters, whereas petrels are a group of birds that are closely related to albatrosses and shearwaters. Fulmars, on the other hand, are medium-sized seabirds that are known for their distinctive tube-like noses. All of these birds are adapted to life at sea and have specialized features that allow them to survive in harsh marine environments.