Also known as the Masked Booby thanks to its distinctive head markings, the Nazca Booby is a well-established Galapagos resident, with the islands being home to approximately 15,000 to 20,000 breeding pairs. The Nazca is the largest of the three booby species that call the Galapagos home, and it looks rather different from it’s more well-known, colored-footed cousins.
Nazca Boobies can be found nesting on several of the Galapagos Islands, but interestingly they stagger their breeding seasons depending on which island they live on. Eggs are typically laid on Genovesa Island between August and November, but that period runs from November to February on Española Island, for example. Galapagos Nazca Boobies aren’t very house proud, though. Their “nests” consist simply of a cleared circular piece of ground lined with their own guano!
Rather grimly, the Nazca Booby chicks are well known for killing their nest mates! The females always lay two eggs, but rather than together, they are laid up to 9 days apart. If the second egg hatches, the older chick always forces the new hatchling out of the nest circle, where it is then ignored by the parents and dies of starvation, cold, or predation. Scientists think the Nazca’s continue to expend the energy needed to lay a second egg despite the fact that it is always condemned to death because it’s an “insurance policy” against the first egg not hatching, or the first chick dying in the first few days of life.
Fast Facts about the Nazca Booby
- Nazca Boobies don't make much effort with their nests - just a scrape in the ground surrounded by a few pebbles
- First-born Nazca Booby chicks will always murder their younger siblings!
- Galapagos is home to the largest breeding colonies of Nazca Boobies in the world
- Nazca Boobies aren't currently threatened, but they are vulnerable to being caught in fishing gear