Petrels are a type of long-winged bird that belong to the Procellariidae family. They are found in all oceans of the world and are known for their ability to fly long distances. They have a distinctive shape, with long wings and a short tail, and they are usually grey or brown in color. Petrels feed mainly on fish, squid, and crustaceans, and they often follow ships to scavenge food. They are also known for their loud calls, which can be heard from far away.