Apart from the striking sexual dimorphism (males are nearly twice as large as females, which is common to all baboons) this species also shows differences in coloration among adults.
 Adult males have a pronounced cape (mane and mantle), silver-white in color, which they develop around the age of ten, while the females are capeless and brown all over.
Their faces range in color from red to tan to a dark brown.

Males may have a body measurement of up to 80 cm (31 in) and weigh 20–30 kg (44–66 lb); females weigh 10–15 kg (22–33 lb) and have a body length of 40–45 cm (16–18 in).
 The tail adds a further 40–60 cm (16–24 in) to the length, and ends in a small tuft.
Infants are very dark brown or black in coloration and lighten after about one year.
 Hamadryas baboons reach sexual maturity at about 4 years for females and between 5 to 7 years for males.
Apart from the striking sexual dimorphism (males are nearly twice as large as females, which is common to all baboons) this species also shows differences in coloration among adults.  Adult males have a pronounced cape (mane and mantle), silver-white in color, which they develop around the age of ten, while the females are capeless and brown all over. Their faces range in color from red to tan to a dark brown.
Males may have a body measurement of up to 80 cm (31 in) and weigh 20–30 kg (44–66 lb); females weigh 10–15 kg (22–33 lb) and have a body length of 40–45 cm (16–18 in).  The tail adds a further 40–60 cm (16–24 in) to the length, and ends in a small tuft. Infants are very dark brown or black in coloration and lighten after about one year.  Hamadryas baboons reach sexual maturity at about 4 years for females and between 5 to 7 years for males.
Hamadryas baboon