Nazca booby

How it lives

Nazca boobies nest in colonies on islands, on bare ground near cliffs. A pair lays one or two eggs. When both hatch, usually only one chick survives, because the older chick pushes out the younger one. Biologists call this obligate siblicide. Both parents care for the young. On Genovesa nesting takes place between August and November, and on Española eggs are laid between November and February. One source gives an average lifespan of about 23 years.

Where it goes

Nazca boobies breed on islands from Baja California to the Galápagos, Isla de la Plata in Ecuador and Malpelo in Colombia. They are mostly seen along the coast and at sea between islands, and are rarely found far offshore. One database lists the bird as partly migratory, but I found no tracking data in the sources I opened. A few stray birds have been recorded as far west as Indonesia and north-western Australia.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

The global population is estimated at 20,000 to 49,999 birds, and the sources call this a minimum estimate (BirdLife International, 2021, as listed on Wikipedia). Numbers are thought to fall to some extent, but not enough to count as a threatened species. Threats named in the sources include introduced predators, human development, long fishing lines, overfishing of its prey and marine pollution. It was long treated as a form of the masked booby and is now recognised as its own species.