Royal Tern
Thalasseus maximus

Physical Description

• Breeding adult: large tern with very pointed wings, a long, forked tail, light gray coloration on back and wings, white coloration below, black tips of wings. Shaggy black crown of feathers on head, black legs, and a thick, dagger-like bright orange bill.
• Non-breeding adult: Similar to breeding adult, rather than a crown have a narrow band of black feathers on back of head.
• Juveniles: Yellow legs, yellow beaks. Spotted feathers of black and gray above with a partial black cap and a gray bar above the wings.

Range

• Breeding: breed off the coast of North Carolina and Virginia, sometimes found northwards.
• Non-breeding: year-round on coasts of southern United States, Mexico, Central America, South America down to Argentina and Peru, Caribbean Islands and coast of West Africa.
• Migrating: migrating along coast of northeast United States.

Habitat

• Found by warm, coastal marine waters.
• Rest and hunt very near shore, occasionally will go offshore when feeding young.
• Nest on sandy beaches, barrier islands, dredged islands.

Reproduction

• Royal terns first breed at age 4 years old.
• Males and females select a ground nest site together in sand; nests are unlined depressions in the sand.
• Females lay 1-2 eggs in the sandy nest. The eggs are 2.3-2.9 inches long and whitish to brown in coloration, and heavily spotted on the longer end.
• The eggs hatch after 28-31 days..
• Royal tern chicks leave the nest within one day of hatching! They join thousands of other chicks in a crèche, or nursery. Their parent finds them in the nursery by their distinct call, and they only feed their own baby. 

Diet

• Sardines, anchovies, silverside minnows, menhaden, bluefish, butterfish, drum, small flying fish.
• Molting crabs, squid, and shrimp.
• Plunge dive to seize prey in bill.

Predators

• Skua, Great Black-backed Gull, Great horned owl, Peregrine falcon have been seen to attack adults.
• Rats, bald eagles, and sand crabs can attack eggs.

Interesting Facts

• When sardines crashed in southern California waters in the early 1950s, the Royal tern numbers also heavily decreased. Elegant terns fed on the anchovies that appeared, and are still numerous today. Royal terns have steadily returned, though not in the numbers they once were. 

Sources: AllAboutBirds.org; BirdsoftheWorld.org; Audubon Field Guide

Photo: Matthew Meier