Inca Tern (Larosterna inca)


Class: Aves
Order: Charadriiformes
Family:    Laridae
Size:    Body: 16 to 22 inches (40 to 56 cm)  Tail: 6 inches (15 cm)  Wingspan: 22 inches (56 cm) 
Weight: 6.7 to 8 ounces (190 to 230 grams)
Diet: Fish, especially anchovies
Distribution: Pacific coast of South America
Young:  1 to 3 chicks, twice a year
Animal Predators:  None
IUCN Status: No special status
Terms: Young: Chick
Lifespan: Up to 20 years



·     The Inca tern is known as a “zarcillo” in Peru, and a “moña” in Chile.

·     Inca terns belong to the same family as gulls.

·     In 1998, the Inca tern was featured on an Antiguan stamp.



Inca terns are unique and beautiful birds—slender with white-tipped gray feathers, a white curly moustache, yellow lips and a bright orange-red bill. They have a distinctive call that sounds like a high pitched laugh, which is often accompanied by bowing gestures.



Inca terns are natives of the western shoreline of South America and the islands located offshore. They are especially abundant in northern Chile and Peru in the summer. They migrate in winter, venturing to Ecuador and central Chile.


Feeding Habits

Inca terns swoop down and pluck fish from near the water’s surface. They also sometimes get scraps left behind by whales, or flock to where sea lions are eating on rocks, to steal stray bits of food.



A male who is interested in a female will perform aerial feats to impress her, as well as bring gifts of fish to her. Once she accepts him, they choose a nest site together in a sheltered area such as a rock crevice or a natural hole in the ground. Inca terns are monogamous and once paired, remain together for life. There are two breeding periods per year—April/May and October/November. After the female has laid the eggs, both the male and female take turns incubating them for the next three to four weeks. Both parents take on the responsibility of feeding the chicks. The chicks begin to walk within a few days and will make their way to the water within a week. At seven or eight weeks, they begin flying, but will remain with the parents for several months and usually will not go far away even once they become totally independent. 



Because of their small legs and tiny webbed feet, Inca terns are not a strong swimmers, but they are very graceful and adept flyers. They can sometimes be seen floating on the water’s surface. They are very social birds that live in large flocks and co-exist peacefully with most other species of birds.  



Inca terns are not a conservation concern. 



Inca Tern Wildlife Fact File, IM Pub, US

Harrison, C. and Greensmith, A. (1993). Birds of the World. London: Dorling Kindersley Limited, p. 154