Nazca Booby

The Nazca booby, Sula granti, is a striking member of the Sulidae family, easily recognized by its long, pointed orange-yellow bill and contrasting plumage. The adult boasts a luminous white body set against black-tipped wings and tail, with a distinctive dark facial mask lending a rather enigmatic appearance.

Identification Tips

When observing the Nazca booby, look for its yellow iris and the orange to pinkish hue of its beak. The black facial skin forms a mask-like feature, and the feet are a subtle grey. Females are generally larger and heavier than males, with a slightly different beak coloration. The male emits a whistling sound, while the female is known for her squawk.

Habitat

This seabird is native to the eastern Pacific, favoring the rocky cliffs and barren ground near the ocean's edge for nesting.

Distribution

The Nazca booby's range extends from the islands off Baja California down to the Galápagos Islands, and further to Isla de la Plata in Ecuador and Malpelo in Colombia.

Behaviour

Nazca boobies exhibit sexual dimorphism in feeding, with females diving deeper and preying on larger fish. They are also known for their long lifespan, low annual reproduction rate, and extended periods of chick development.

Song & Calls

The vocalizations of the Nazca booby are sexually dimorphic: males whistle, while females squawk, each sound serving as a means of communication and identification among these seabirds.

Breeding

Breeding takes place near cliffs, with males establishing and defending territories to attract females. The species is known for its low hatching success and the common occurrence of siblicide when two eggs are laid.

Similar Species

While once considered a subspecies of the masked booby, the Nazca booby can be distinguished by its genetic and behavioral differences.

Diet and Feeding

The Nazca booby's diet consists mainly of small fish like the South American pilchard, but it also includes flying fish, anchovies, and squid. These birds are adept at diving from great heights to capture their prey, particularly during El Niño events when their usual food sources are scarce.

Conservation status

The IUCN lists the Nazca booby as Least Concern, though factors such as overfishing and marine pollution are causing some population decline. However, this decline is not currently significant enough to warrant a higher threat category.