Red-tailed Tropicbird

Phaethon rubricauda
Red tailed tropicbird

Mature birds have mostly white plumage with a conspicuous black stripe from gape, curving towards and passing through eye. Strong decurved, bright, red, heavy beak. Legs and feet are blue-gray with webs distally black. White tail with long, red, central rectrices (36-55 cm).

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). 

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.

In 2007 it was estimated that there are 100 red-tailed tropicbirds were present on the Atoll, largely on Wake Island. Several pairs were seen prospecting on Wilkes Island, both in the designated refuge area and along the shore near the Prisoner of War Memorial.

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)