Gull's cousin is a term used to refer to two species of seabirds, the TERN and the ERNE. The TERN is a medium-sized seabird with long wings, a forked tail, and a slender body. It is found in temperate and tropical regions around the world. The ERNE is a large seabird with a long neck, long wings, and a short tail. It is found in temperate and subarctic regions of Europe, Asia, and North America. Both species are known for their graceful flight and their ability to dive for food.