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
Common kingfisher litter of fish remains and cast pellets. The common kingfisher typically lays two to ten glossy white eggs, which average in breadth, in length, and weigh about , of which 5% is shell. One or two eggs in most clutches fail to hatch because the parent cannot cover them. Both sexes incubate by day, but only the female at night. An incubating bird sits trance-like, facing the tunnel; it invariably casts a pellet, breaking it up with the bill. The eggs hatch in 19–20 days, and the altricial young are in the nest for a further 24–25 days, often more.