Nazca boobies are the largest of the booby birds in the Galapagos Islands. In this post, you’ll learn 26 Nazca booby facts – from range, diet, mating rituals, and obligate siblicide (yes, it’s as scary as it sounds). Plus lots of photos and videos.
Guide to the Nazca Booby in the Galapagos
There are several kinds of booby seabirds, but did you know about the Nazca booby? Not only is it the largest of all the booby species, but it wears a black eye mask and practices a unique (and shocking) behavior called obligate siblicide.
Want to know more? Continue reading because we offer everything you need to know about this seabird in the following 26 Nazca booby facts.
Nazca Booby Overview
- Latin Name: Sula granti
- Range: Eastern Pacific islands and coasts of Ecuador and Peru
- Population Status: Estimated 30,000 individuals
- Size: Weight: 3 to 5 pounds (1.2 to 2.3 kg); Height: 30 to 35 inches (75 to 89 cm)
- Wingspan: 5 to 6 ft (1.5 to 1.8 m)
- Diet: Squid, flying fish, anchovies and sardines
- Notable Features: Black eye mask; practices obligate siblicide
- Where it lives in Ecuador/Galapagos: Española Island, San Cristóbal Island, Genovesa Island, and Daphne Major
26 Nazca Booby Facts
1. Where does the Nazca booby live?
The Nazca booby is native to the islands of the eastern Pacific Ocean, including Baja (California), Isla de la Plata (Ecuador), Malpelo (Colombia), Clipperton Island, and the Galapagos Islands where it primarily breeds.
A few small populations are also found breeding on the coasts of Ecuador and Peru.
2. What is the habitat of the Nazca booby?
Because of its goose-like size and weight, the Nazca booby is not able to launch off in flight from just anywhere. So, it prefers staying close to rocky cliffs where taking off is easier.
3. Where do Nazca boobys nest?
Nazca boobies nest in colonies on cliff ledges and steep, rocky slopes nearby the ocean. The male chooses a nest site on a cliff ledge where there is little or no vegetation and lines it with guano.
After settling the nest site, the male goes about attracting a female by doing a mating dance ritual that involves pointing at the sky with his long beak. When a female decides to accept him, she will also do the sky-point dance.
Together, the two will bob their heads up and down and knock their beaks together. This dance ritual makes a depression on the ground where the eggs will soon be laid.
4. What does the Nazca booby look like?
- The largest of all the booby species breeding on the Galapagos Islands, the Nazca booby is mostly white with a black tail and black wingtips.
- It has a yellow or orange bill, gray feet, and a black eye mask that sometimes confuses people into thinking it’s the masked booby.
- The female is usually larger than the male and has a paler-looking bill.
- The Nazca booby and the masked booby were once considered the same species but now are distinguished as two different species. The masked booby differs in size, bill color and range.
5. How does the Nazca booby differ from the masked booby?
Before being classified as its own species in 2002, the Nazca booby was considered a close relative of the masked booby.
The primary differences between the Nazca and masked boobies are in their appearance and their behavior.
- The Nazca booby prefers to nest on cliffs and other steep slopes, while the masked booby nests in the lowlands.
- The masked booby, looking surprising similar to the Nazca, has a shallower and deeper yellow beak.
6. How tall is a Nazca booby?
An adult Nazca booby can grow from 30 to 35 inches (75 and 89 cm) in height.
7. How much does a Nazca booby weigh?
With females being somewhat larger than males, Nazca boobies can weigh between 3 and 5 pounds (1.2 and 2.3 kg).
8. What is the Nazca booby’s wingspan?
A Nazca booby wingspan ranges from 5 to 6 feet (1.5 to 1.8 m).
9. How did the Nazca booby get its name?
The Nazca part of its name comes from the region of the Nazca oceanic tectonic plate in which the Nazca booby inhabits.
The “booby” part derives from the Spanish word “bobo,” which means “foolish” or “clown” because this bird looks a little silly and clumsy when it walks on land.
10. Are Nazca boobys friendly or agressive?
Nazca boobies can be aggressive toward one another when defending their nest sites. They aren’t afraid of people on the Galapagos Islands, nor do they pose a threat to humans.
Nazca booby chicks are extremely aggressive toward their siblings, even to the point of killing them. You can read more about this in point #21.
11. How long do Nazca boobys live?
Like many other seabirds, Nazca boobies have a long lifespan, living up to 25 years.
12. What eats a Nazca booby? Predators and Threats
Due to its large size, nothing really eats the adult Nazca booby except for the Galapagos hawk and the occasional shark. Birds of prey and introduced pigs sometimes steal the eggs or chicks.
The vampire finch is known to feed on the blood of the Nazca booby by pecking at its wings and tail, but this doesn’t appear to harm the booby. In fact, the Nazca booby doesn’t seem to mind at all.
As far as threats go, humans are the main menace by creating plastic pollution and longline fishing which drowns the birds when they try to capture bait on the lines.
Fortunately, conservation programs are currently working to diminish these threats.
13. Are Nazca boobys extinct or endangered?
No, Nazca boobies are not extinct or endangered.
In fact, the IUCN (International Union for Conservation of Nature) classifies this seabird as Least Concern. While they do face threats, their populations have not declined enough to warrant an endangered classification.
14. What do Nazca boobys eat?
The favorite food of Nazca boobies is pilchards, but they also eat squid, flying fish, and anchovies.
15. How do Nazca boobys hunt?
Together in large flocks, Nazca boobies hunt by plunge-diving into the ocean at high speeds as deep as 98 feet (30 m).
Because females are larger than males, they can dive deeper and eat larger prey than males.
16. What is the Nazca booby’s Latin name?
- Class: Aves
- Order: Suliformes
- Family: Sulidae
- Genus: Sula
- Species: S. granti
17. Do Nazca boobys mate for life?
Like their cousins, the red footed and blue footed boobies, Nazca boobies tend to form monogamous bonds and mate for life.
But, they are also known to occasionally choose a different mate if their mate doesn’t show up during breeding season or if another Nazca booby intrudes the nest and “home-wrecks” the breeding couple.
Nazca Booby Mating Ritual
Watch on YouTube
18. At what age do Nazca boobys lay eggs?
Nazca boobies lay eggs when they have reached sexual maturity, which is around 3 or 4 years of age.
19. How often do Nazca boobys lay eggs?
These boobies lay eggs once per breeding season (about every nine months), but this varies according to the location of their colony. Colonies on different islands breed at different times of the year.
Here’s a rare glimpse of a Nazca booby laying eggs in the wild.
Watch on YouTube
20. How many eggs does the Nazca booby lay? What do they look like?
Female Nazca boobies lay between one and two eggs per clutch. The eggs are white with light brown speckles.
Both parents incubate the eggs for about 40 days but in an unusual way. These boobies don’t have a brood patch like other birds. So, they use their large, webbed feet to incubate the eggs because their feet are made with many blood vessels that provide heat, especially during the nesting period.
21. What is obligate siblicide?
Obligate siblicide is a behavior of Nazca booby chicks in which the oldest chick kicks its younger sibling out of the nest, causing it to die from either temperature change, predation, or starvation.
Nazca boobies lay their two eggs several days apart. When the first chick hatches, it has time to grow strong by the time the second chick hatches. After the younger chick is born, the older one will become aggressive toward it and commit siblicide.
Other boobies may practice this behavior only when food sources are limited. With the Nazca booby, it occurs every time regardless of the food supply. This is what makes it obligate siblicide.
Here’s more about Nazca booby siblicide. Warning: this might be disturbing for some readers.
Watch on YouTube
This behavior exists among other young birds. For example, shoebill chicks from Africa will fight each other until the dominant one is chosen by its mother to survive.
22. What is the Nazca booby’s call?
The call of the Nazca boobies is one way to distinguish their gender because males make a whistling sound while females quack. When they’re out to sea, they rarely make any vocalizations.
23. Are Nazca boobys loud?
These boobies can get loud when they’re squabbling over food or practicing their mating dance. Otherwise, they’re not too loud.
24. Do Nazca boobys carry disease?
Like other birds on the Galapagos Islands, Nazca boobies are at risk for diseases like avipoxvirus, salmonella, and avian malaria as well as infections caused by parasites and lice. However, they are not known to spread any contagious diseases to humans.
Thankfully, the Galapagos National Park, the Charles Darwin Research Station, and other outside conservation teams all work together to keep tabs on the birds living on the Galapagos archipelago to prevent the spread of bird diseases.
25. Where can I see the Nazca booby?
You can see Nazca boobies in the Galapagos Islands pretty much all year round. They’re often seen flying, but if you want to see them on land, the best places are Punta Pitt (San Cristóbal Island), Punta Suarez (Española Island), Genovesa Island, and Daphne Major.
They’re usually not afraid of people, but researchers say that in recent years these boobies are beginning to nest further away from the presence of humans.
I’m not sure if there are any Nazca boobies in zoos or not – I’ve been unable to find any. Some zoos and wildlife refuges may take in these boobies temporarily if they’ve been rescued from injury or disease.
26. Types of booby birds in the Galapagos Islands
Booby seabirds belong to the genus Sula. There are six species of boobies in the world. The Sula species that aren’t found in the Galapagos include: brown, masked, and Peruvian.
Learn more about other Galapagos Islands animals.
From its funny appearance to its alarming nest practices, the Nazca booby is a unique and interesting creature.
What did you think of these Nazca booby facts? Were you surprised by any of them? Have you ever seen a Nazca booby in person? Please share your thoughts in the comments section.