Marine life same environmental problems and feeding niches have resulted in similar adaptations. Examples include albatross, penguins, gannets, and auks. In general, marine birds live longer, breed later and have fewer young than terrestrial birds do, but they invest a great deal of time in their young. Most species nest in colonies, which can vary in size from a few dozen birds to millions. Many species are famous for undertaking long annual migrations, crossing the equator or circumnavigating the Earth in some cases. They feed both at the ocean's surface and below it, and even feed on each other. Marine birds can
Southern cassowary occurrence range of , and between 10,000 and 20,000 birds were estimated in a 2002 study, with between 1,500 and 2,500 in Australia. Southern cassowaries have been bred in many zoos around the world, like at White Oak Conservation in Yulee, Florida, United States. Southern cassowary The southern cassowary ("Casuarius casuarius"), also known as double-wattled cassowary, Australian cassowary or two-wattled cassowary, is a large flightless black bird. It is a ratite and therefore related to emu, ostrich, and the "Rhea" and Kiwi genera. (See also dwarf cassowary and northern cassowary.) Presently, most authorities consider the southern cassowary monotypic, but several