Nazca Booby

Sula granti

Until 2000, scientists believed this bird to be a subspecies of the Masked Booby until DNA analysis determined these to be separate species. Estimates are that the Nazca split from the Masked Booby less than a million years ago. The Masked Booby has a yellow bill, where the Nazca Booby has an orangish bill.

Most Nazca Boobies breed in the Galapagos Islands. But there are also breeding colonies in the Malpelo and Revillagigedo Archipelagos.

Taxonomists consider the Nazca Booby to be monotypic (i.e. there are no subspecies). Evolution has provided boobies with special adaptations to accommodate their foraging style. One of these traits are the closed external nostrils, and secondary nostrils beside the mouth. These are covered by moveable flaps when the bird plunge-dives into the sea.

Both Masked and Nazca Boobies have been expanding their non-breeding ranges north. They have been occasionally sighted in San Diego waters. I met them both during the south-bound leg of our 2017 expedition to the Revillagigedo Archipelagos.