The GalÃ¡pagos Penguin (Spheniscus mendiculus) is a penguin common to the GalÃ¡pagos Islands. It is the only penguin to live on the equator. Its nearest relatives are the African Penguin, the Magellanic Penguin and the Humboldt Penguin. The GalÃ¡pagos Penguin occurs primarily on Fernandina Island and the west coast of Isabela Island, but small populations are scattered on other islands in the GalÃ¡pagos archipelago.
GalÃ¡pagos Penguins grow to an average of 53 cm tall. They have a black head with a white border running from behind the eye, around the black ear-coverts and chin, to join on the throat. They have blackish-grey upperparts and whitish underparts, with two black bands across the breast, the lower band extending down the flanks to the thigh. Juveniles differ in having a wholly dark head, greyer on side and chin, and no breast-band.
The GalÃ¡pagos Penguin is monogamous and thus mates for life. It lays one or two eggs in places such as caves and crevices, protected from direct sunlight which can lead to the eggs overheating. One parent will always stay with the eggs or chicks while the other is absent for several days to feed. If there is not enough food available, the nest may be abandoned.
The species is endangered, with an estimated population size of around 1,500 individuals in 2004, according to a survey by the Charles Darwin Research Station. The population underwent an alarming decline of 65% in the 1980s, but is slowly recovering. It is therefore the rarest penguin species (a status which is often falsely attributed to the Yellow-eyed penguin). Population levels are influenced by the effects of the El NiÃ±o Southern Oscillation, which reduces the availability of shoaling fish, leading to low reproduction or starvation. However, anthropogenic factors (e.g. oil pollution, fishing by catch and competition) may be adding to the ongoing demise of this species. On Isabela Island, the introduced cats, dogs and rats may attack penguins and destroy their nests.