Inca Tern  Larosterna inca 

Peruvian Name: Zarcillo
Range: Chile and Peru
Status: Abundant species
Diet in Wild: Anchovies and squat lobsters
Diet in the Zoo: Tiny Smelt and/or vitamins

Location in the Zoo:  not currently on exhibit.


*Physical Description
*General Information
*Special anatomical, physiological or behavioral adaptations
*Comments about Inca Terns of the Fort Worth Zoo


*Source Materials and Related Links


Physical Description

Height can be from 16” to 22”. Weight varies 190 – 230 grams. A beautiful, slenderly built bird, with slate-colored plumage, crimson bill and legs, yellow gape wattles, and a whisker–like ornamental white plume near each eye. 
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General Information

In a simple courtship ritual, the male Inca Tern engages in skillful aerial display to impress the female. He also pursues her in the air with gifts of fish until she finally accepts him. The pair then chooses a nest site unlike most terns, which tend to nest on open ground. Instead, Inca Terns select sheltered nest sites. The birds often return to the same nest site years in a row. The female lays one to three eggs, which the male and female incubate for three to four weeks. Young chicks are then able to fly after 7 weeks.
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Special anatomical, physiological or behavioral adaptations

The Inca Tern is a graceful flier but is not a strong swimmer, its webbed feet are too small to propel it through the water effectively. It is, however, able to float on the surface. The Inca Tern fishes for its prey by hovering over water at a height of around 50 feet. The bird then swoops down and emerges almost immediately with its catch. In addition, the birds hover in a big flock when sea lions haul out onto rocks in order to eat. The Inca Terns then plunge down onto the sea lions and actually take the chewed-up food from between their teeth. The Inca Tern specializes in a high-pitched “laughing” or “cackling” call, often in conjunction with bowing or other gestures.
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Comments about Inca Terns of the Fort Worth Zoo:

Unfortunately, the Inca Terns are no longer available at the Fort Worth Zoo, due to an expansion in Raptor Canyon. Hopefully, we will see them again in the future.
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Personal Observations:

Personally, I did not know anything about terns, let alone the Inca Tern, but I have come to learn that the Inca tern is a beautiful bird, not only because of its distinctiveness, but because of its rich coloring .   I haven’t seen such a dramatic look ,since the peacock. 
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Source Materials and Related Links

*The Oregon Zoo. Inca Tern. 6 Oct. 1999.
*Animal Diversity Web Page. University of Michigan. Inca tern.$media.html
*The Peruvian Seabirds Homepage. The Inca Tern. 7 Oct. 1999.


*Dr.Dr.hc. Bernard Grzimek. “The Inca Tern”. Grzimek’s Animal Life Encyclopedia.Volume 8 : Birds II.


*Oliver L. Austin, Jr. Birds of the World. Ed. Herbert S. Zim   New York City: Golden Press,1961


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Last revised: April 14, 2003