Red-billed Tropicbird

Phaethon aethereus




Tropicbirds (Phaethontidae)

Code 4


Code 6



Egg Color:

Red brown or white buff with blotches or spots.

Number of Eggs:


Incubation Days:


Egg Incubator:

Both sexes

Nest Location:

Scrape, crevice, or preformed burrow, in a cave, under shrub, or on bare ground.

Nest Material:






Red-billed Tropicbird: Slender white seabird with long white tail streamers; white back, finely barred with black. Black eye stripe curves upward behind eye and almost meets at nape. Their primaries are black; red bill; base of central toe and variable length of outer toes orange-yellow, rest of feet black. Sexes are similar; streamers longer on male. Juveniles' tail feathers have black tips or sub-terminal dots, lack tail streamers; black collar; white crown; postocular stripes meet on nape; may have black markings on flanks and lateral undertail coverts.

Range and Habitat

Red-billed Tropicbird: Found in warm open ocean waters, often far from shore. Breeds on remote coastal islands or occasionally coastal mainland of Pacific Mexico and Caribbean. Occasional visitor off the Atlantic and Pacific coasts of Florida and California. Rare to Gulf Coast, one record for Arizona.

Breeding and Nesting

Red-billed Tropicbird: Monogamous semi-colonial nester. Scrape nest built by both male and female in a cave or burrow, sometimes on ground, always close to shore. Female lays one blotched or spotted red brown or white buff egg. Both sexes incubate for approximately 44 days and tend young until fledging. Young may stay in nest for up to 12 weeks.

Foraging and Feeding

Red-billed Tropicbird: These birds usually forage alone. They typically fly high above the water with direct, fast and shallow wing-beats, sometimes hovering before plunge-diving to catch fish or squid. They are fond of flying fish and sometimes take them from the air. They are clumsy and helpless on land, where they slowly push themselves along on their belly using their wings and feet.


Red-billed Tropicbird: Shrill and grating tern-like rattles often repeated in breeding colonies. Usually silent at sea.

Similar Species

Red-billed Tropicbird: Red-tailed tropicbird is smaller, with more white overall, and red tail streamers. Lacks fine black barring on back.

Undertail covertsX
Small feathers that cover the areas where the retrices (tail feathers) attach to the rump.
Also called the hindneck or collar, it is the back of the neck where the head joins the body.
The primaries are the flight feathers specialized for flight. They are attached to the "hand" equivalent part of the wing.
The ventral part of the bird, or the area between the flanks on each side and the crissum and breast. Flight muscles are located between the belly and the breast.
Parts of a Standing bird X
Head Feathers and Markings X
Parts of a Flying bird X