Sandwich tern Sterna sandvicensis

• Sexes similar
• Dives into water for prey
• Large tern with long, thin, black bill with yellow tip
• Fairly long, deeply forked tail
• Spiky crest at the rear of the head
• Pale underwing with dark tips to outer primaries

Adult alternate:

• Black legs
• Black cap
• White face, neck, breast, and belly
• Pale gray back and upperwings
• White rump and tail

Adult basic:

• White forehead and streaked crown
• Black mask extends rearward from eye to spiky crest at rear of head

Juvenile:

• Similar to adult basic but has dark feather edgings to mantle
• Yellow tip to bill may not be evident
• Occasionally have yellowish bills

Similar species:

The smaller Sterna terns have shorter black or black-tipped bills (not yellow-tipped), slimmer bodies and wings and a more deeply-forked tail. Larger terns have red or orange bills.