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.
Kori bustard
The male kori bustard is , stands tall and may have a wingspan about . Male birds may typically weigh between . The average weight of adult males of the nominate race in Namibia (20 specimens) was , while "A. k. struthiunculus" males were found to average . The larger excepted males can scale up to and a few exceptional specimens may weigh up to at least . Reports of outsized specimens weighing , and even "almost" have been reported, but none of these giant sizes have been verified and some may be from unreliable sources. Among bustards, only male great bustards ("Otis tarda") achieve similarly high weights, making the male kori and great not only the two largest bustards but also arguably the heaviest living flying animals. As a whole, other species, such as Dalmatian pelican ("Pelecanus crispus"), Andean condor ("Vultur gryphus") and trumpeter swan ("Cygnus buccinator"), might weigh more on average between the sexes but are less sexually dimorphic in mass than the giant bustards. The female kori bustard weighs an average of , with a full range of . Females of the nominate race (35 specimens) in Namibia weighed a mean of , while females from "A. k. struthiunculus" weighed a mean of . Female length is from and they usually stand tall and have a wingspan of . The standard measurements of the male include a wing chord of , a tail measures from , a culmen from and a tarsus from . Meanwhile, the female's standard measurements are a wing chord of , a tail of , a culmen from and a tarsus from . Body mass can vary considerably based upon rain conditions.