Common ostrich other members of Palaeognathae and thus the flighted tinamous are the sister group to the extinct moa. It is distinctive in its appearance, with a long neck and legs, and can run for a long time at a speed of or even up to about , the fastest land speed of any bird. The common ostrich is the largest living species of bird and lays the largest eggs of any living bird (extinct elephant birds of Madagascar and the giant moa of New Zealand laid larger eggs). The common ostrich's diet consists mainly of plant matter, though it also eats
Bird nest bird. The flow-on consequence of this is that nest insulation is also related to parent mass. The "saucer" or "plate" nest, though superficially similar to a cup nest, has at most only a shallow depression to house the eggs. The "platform" nest is a large structure, often many times the size of the (typically large) bird which has built it. Depending on the species, these nests can be on the ground or elevated. In the case of raptor nests, or "eyries" (also spelt "aerie"), these are often used for many years, with new material added each breeding season. In some