The Procellariidae family, encompassing fulmarine petrels, gadfly petrels, diving petrels, prions, and shearwaters, have a significant presence within the order Procellariiformes, also known as tubenoses, which includes albatrosses and storm petrels. With great diversity and numerous species, these seabirds range from the large giant petrels, comparable to albatrosses, to the much smaller diving petrels. Both male and female procellariids appear identical and typically exhibit muted colors such as black, white, brown, and gray within their plumage. These birds are predominantly adept swimmers and foragers, feeding on fish, squid, crustaceans, and sometimes scavenging leftovers from fisheries or carrion. They are efficient at long-distance foraging and many migrate across equatorial distances. When breeding, procellariids are known to show loyalty to both their partners and nesting sites, laying a single egg that both parents take turns incubating. Despite this, not all species fare well; while some procellariids have burgeoning populations, others are endangered, threatened by predation from introduced species in their breeding habitats and by bycatch in long-line fisheries.
Historically, these birds have been exploited by humans for food and other uses, yet this practice persists on a more regulated scale today. Taxonomic studies have reshaped the understanding of their relationship within Procellariiformes, grouping the diving petrels into the same family due to genetic studies. Different procellariid groups are linked by characteristics such as skull features or diving abilities, and despite their varied appearances and habits, they share certain traits like weak legs and specific flight adaptations that assist them in their oceanic lives. They employ dynamic and slope soaring techniques to glide over waves and winds, with some species possessing a special shoulder-lock that aids in effortless flight. The family is spread across the world's oceans and undertakes remarkable migrations, but many species are restricted to isolated regions or specific latitudes. With well-developed senses, particularly for smell, they are able to locate their prey with astonishing accuracy. Though their relationship with humans has sometimes been detrimental, conservation efforts are underway to mitigate threats and protect the more vulnerable species.