A large seabird of tropical oceans, the Masked Booby is only a rare visitor to North America. It has attempted to breed in the Dry Tortugas in Florida, but it is most frequently encountered at sea in the Gulf of Mexico or off the southern Atlantic states.
The population of Masked Boobies breeding along the Pacific Coast of northern South America, including the Galapagos, was recently recognized as a separate species, the Nazca Booby. The Nazca Booby has an orange, not yellow, bill and is smaller with a significantly shorter, shallower bill. Whereas the Masked Booby usually nests on low, flat areas, the Nazca Booby uses cliffs and steep slopes.
Although the Masked Booby regularly lays two eggs, it never raises two young. The first egg is laid four to nine days before the second, and the older chick always ejects the second from the nest. The parents do not protect or feed the ejected chick, and it is quickly scavenged by a host of associated crabs, landbirds, and frigatebirds.
Bibliographic Citation: "Masked Booby (Sula dactylatra)." The Cornell Lab of Ornithology All About Birds.
Citation Link Accessed 27 Jan 2014.
