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.
Bostryx turritus
Zilch (1953) reports "Bostryx turritus turritus" (shell height/shell width = 3.25) from Hacienda El Casa Grande (probably near 07°40’S 078°40’W) in La Libertad Region, and described "Bostryx turritus tamboensis" (shell height/shell width = 2.87) from the same locality, albeit from different elevations (1500 m resp. 1000 m). According to Haas (1955) – reporting a locality at 1360 m – his shells ‘are slightly more slender than the typical form’. The specimens from Catzcal show a variation in ration shell height/shell width from 2.84 to 3.18 (mean 3.00; n = 7). It is possible that this variation can also be found in the populations at the localities in La Libertad, in which case "Bostryx turritus tamboensis" should be considered a synonym of the nominate taxon.