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
Tit (bird) caching, hoarding supplies of food during the winter. Tits are cavity-nesting birds, typically using trees, although "Pseudopodoces" builds a nest on the ground. Most tree-nesting tits excavate their nests, and clutch sizes are generally large for altricial birds, ranging from usually two eggs in the rufous-vented tit of the Himalayas to as many as 10 to 14 in the blue tit of Europe. In favourable conditions, this species had laid as many as 19 eggs, which is the largest clutch of any altricial bird. Most tits are multibrooded, a necessary strategy to cope with either the harsh winters in which