Largest organisms is frequently poorly documented and many are subject to conjecture and estimation. The largest living bird, a member of the Struthioniformes, is the common ostrich ("Struthio camelus"), from the plains of Africa and Arabia. A large male ostrich can reach a height of and weigh over . A mass of has been cited for the common ostrich but no wild ostriches of this weight have been verified. Eggs laid by the ostrich can weigh and are the largest eggs in the world today. The largest bird in the fossil record may be the extinct elephant birds ("Aepyornis") of Madagascar, which
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