Many birds and animals use Macquarie Island to breed. About 3.5 million seabirds and 80,000 elephant seals come to the island every year. Four types of penguins live on the island. There are about 850,000 royal penguins, 200,000 king penguins, 10,000 gentoo penguins, and rockhopper penguins with numbers thought to be between 20,000 and 1,000,000.