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
Palaeognathae flying birds that were common in the Cenozoic of the northern hemisphere, were also paleognaths. He argues that the lithornithiform bird "Paleotis", known from fossils in Denmark (northern hemisphere), shared unique anatomical features of the skull that make it a member of the same order as the ostriches. He also argued that the kiwis should not have reached New Zealand, which moved away from the mainland in the Early Cretaceous, if their ancestor was flightless; this claim at least has been vindicated by the discovery of the possibly volant "Proapteryx". He therefore deduced that lithornithiform ancestors could have reached the