Nazca boobies courting. This was taken at sunset on top of a seaside cliff with sea mist in the background. (From Wikipedia: The Nazca Booby, Sula granti, is a booby which is found in the eastern Pacific Ocean, namely on the Galápagos Islands and on Clipperton Island. Nazca boobies are known for practicing habitual siblicide. They lay two eggs, several days apart. If both eggs hatch, the elder chick will push its sibling out of the nest area, leaving it to die of thirst or cold. The parent booby will not intervene and the younger chick will inevitably die. It is believed that two eggs are laid so that one remains an insurance in case the other gets destroyed or eaten e.g. by gulls, or the chick dies soon after hatching.)