Common ostrich
Common ostriches usually weigh from , or as much as two adult humans. The Masai ostriches of East Africa ("S. c. massaicus") averaged in males and in females, while the nominate subspecies, the North African ostrich ("S. c. camelus"), was found to average in unsexed adults. Exceptional male ostriches (in the nominate subspecies) can weigh up to . At sexual maturity (two to four years), male common ostriches can be from in height, while female common ostriches range from tall. New chicks are fawn in colour, with dark brown spots. During the first year of life, chicks grow at about per month. At one year of age, common ostriches weigh approximately . Their lifespan is up to 40–45 years.
Somali ostrich
Though generally similar to other ostriches, the skin of the neck and thighs of the Somali ostrich is grey-blue (rather than pinkish), becoming bright blue on the male during the mating season. The neck lacks a typical broad white ring, and the tail feathers are white. The females are slightly larger than the males and browner in plumage than other female ostriches. The Somali ostrich is similar in size to other ostrich so far as is known, perhaps averaging marginally smaller in body mass than some subspecies of common ostrich (at least the nominate race, "S. c. camelus"). Reportedly Somali ostriches in captivity weigh about but this may not be an accurate weight for wild birds as captive animals have feeding accesses not available to wild ostriches. It is thus one of the two largest extant bird species.