Red-tailed Tropicbird

Koa‘e‘ula / Phaethon rubricauda
Red-tailed tropicbird


  • Found at Kīlauea Point February - October
  • In Hawaiian koa‘e refers to tropic birds while ‘ula means red
  • Mature birds have mostly white plumage with a conspicuous black stripe from gape, curving towards and passing through the eye. They have a strong decurved, bright red, heavy beak. Their legs and feet are blue-gray with webs distally black. White tail with long, red, central rectrices that give the bird its name.
  • Their calls are a guttural squawk in varying intensities and/or high whistle-like screeches.
  • They perform complex aerial courtship displays. Acrobatics consist of flying backwards, vertical displays and circles. Pair bonding behavior is minimal.
  • Birds begin breeding after 4 years of age. They nest year round with peak activity from March through August. Adults generally return to the same nest site each year. Nest sites are usually located in sheltered areas from the sun (base of a tree, in shrubs, next to a structure).
  • Tropicbirds are pelagic birds meaning they spend the majority of their life on the open ocean and only venture back to land to breed. Pelagic birds are powerful fliers with exceptionally long, thin wings. They can remain in flight for days or weeks, sleeping in-flight, while staying hundreds to thousands of miles offshore. They also have a special salt gland that helps them extract excess salt from their body. This allows them to drink seawater and ingest water from prey without accumulating toxic levels of salt in their bloodstream.
  • The female lays a single egg, ranging in color from brown to purplish black, allowing them to recognize and retrieve their own eggs. Relaying can occur if the first egg is lost or infertile. Incubation period varies from 39-51 days. Both parents incubate the egg. Average incubation shift lengths range from 8-9 days.
  • During the first few weeks after hatching, chicks are attended and fed by one of its parents in shifts similar to those during incubation. Nestlings are brooded almost continuously for the first week. Feeding takes place on an average of every 17 hours. Unlike other Pelecaniformes, adults regurgitate food by putting their bills down the gaping chick's throat.
  • The chick-rearing period can range from 77 to 123 days. Chicks reach adult weight in six weeks. In 11 weeks, wing exercising begins and in 12-13 weeks, fledging occurs. Chicks fledge with a dark gray bill and white and gray plumage.

Facts About Red-tailed Tropicbird


Usually feeding during the day, are solitary feeders and rarely fish within sight of land. They dive, wings half-folded, into the water to catch their prey. Red-tails consume mostly fish (flying fish, mackerel, dolphinfish, balloonfish) and squid. Their diet is about 4/5 fish and 1/5 squid.

Life Span
16 years

Length: 44-47 cm (17-18 in), 80-102 cm including tail streamers; wingspan: 104 cm (41 in)