It is estimated that there are more than 42 million penguins in the world. An exact number is difficult to obtain due to fluctuations in the populations of some species of penguin.
There are 17 different penguin species. With an estimated 9 million breeding pairs, the most populous species is the macaroni penguin, which lives on islands in the Subantarctic and on the Antarctic peninsula. Galapagos penguins, which live on the Galapagos islands off the coast of Ecuador, have the lowest population at about 1,200 mature individuals.
Many species of penguin are listed as threatened or endangered by the Endangered Species Act, but some species, such as the Adelie penguin, are increasing their numbers.