The African Penguin, also known as the Black-footed Penguin is found on the south-western coast of Africa, living in colonies on 24 islands between Namibia and Algoa Bay, near Port Elizabeth, South Africa, with the largest colony on Dyer Island, near Kleinbaai. Two colonies were established by penguins in the 1980s on the mainland near Cape Town at Boulders Beach near Simon's Town and Stony Point in Betty's Bay. Mainland colonies probably only became possible in recent times due to the reduction of predator numbers, although the Betty's Bay colony has been attacked by leopards. The only other mainland colony is in Namibia, but it is not known when this was established. Boulders Beach is a tourist attraction, for the beach, swimming and the penguins. The penguins will allow people to approach them as close as a meter (three ft). The closest relatives of the African Penguins are the Humboldt Penguin and Magellanic Penguins found in southern South America and the Galápagos Penguin found in the Pacific Ocean near the equator. African penguins grow to 68-70 cm (26.7-27.5 in) tall and weigh between 2 and 5 kilograms (4.4 and 11 lb). They have a black stripe and black spots on the chest, the pattern of spots being unique for every penguin, like human fingerprints. They have pink glands above their eyes. The hotter the penguin gets, the more blood is sent to these glands so it may be cooled by the surrounding air, thus making the glands more pink. The males are larger than the females and have larger beaks, but their beaks are more pointed than those of the Humboldt. Their distinctive black and white colouring is a vital form of camouflage - white for underwater predators looking upwards and black for predators looking down onto the dark water. African Penguins breed throughout the year. Of the 1.5-million African Penguin population estimated in 1910, only some 10% remained at the end of the 20th century.