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.
Common ostrich
A key point when looking at the common ostrich metabolism is to note that it is a non-passerine bird. Thus, BMR in ostriches is particularly low with a value of only 0.113 ml O g h. This value can further be described using Kleiber's law, which relates the BMR to the body mass of an animal.