Considered sacred by the ancient Egyptians, the hamadryas baboon (Papio hamadryas) is distinguished from other baboons by the male’s long, silver-grey shoulder cape, and the pink or red rather than black face and rump. Like all baboons, the hamadryas baboon is a large monkey with a dog-like face, pronounced brow ridges, relatively long limbs with short digits, rather coarse fur, and a relatively short tail, which in this species has a tufted tip. The male is considerably larger than the female, and has a heavy cape, bushy cheeks, and large canine teeth. While the male hamadryas baboon develops a silvery-grey coat, the juvenile and female are brown, with dark brown skin on the face and rump. The female hamadryas baboon develops colourful and pronounced sexual swellings during oestrus, and the skin over the rump becomes bright red during pregnancy. This species sometimes hybridises with the olive baboon (Papio anubis) where the ranges of the two overlap, in a small area of northern Ethiopia.