long streamer-like tails adult tropicbirds are easy to identify. The
only other streamer-tailed seabirds in the region are Long-tailed
Jaegers, which are dark, not white. This tropicbird’s total length is
about 46-50 cm, not including streamers, compared to the total length
of the smaller White-tailed (36-40 cm without streamers).
streamer tail, barred dorsal surface. Adult White-tailed
can have orange red bills, but lack the dorsal barring.
barring on dorsal surface, blackish eye stripe joined across back of
head. Bill yellow with black tip. Juvenile
has much courser and less dense barring on back.
Tropicbird is the largest, least common, and most narrowly distributed
of the three species of Phaethon.
Three subspecies of Phaethonaetherus
are recognized, two of which occur in the Atlantic. Tropicbirds have
until 2008 been classified as primitive members of the Order
and are still grouped with those birds. However, a recent paper
using 19 different nuclear DNA regions found that Tropicbirds are most
closely related to Columbiformes
(Pigeons and allies), Mesites,
If this result bears out, tropicbirds will be their own group of
convergently evolved seabirds, and the field guides will all have to be
At and near
breeding sites, remains at sea throughout remainder of the year.
P. a. mesonauta
occurs in the eastern Pacific (including the Galapagos Islands),
Caribbean, and the Cape Verde Islands. Other subspecies are found in
the tropical South Atlantic and the Red and Arabian Seas and the
Persian Gulf. Regionally the species nests primarily in the Lesser
Antilles, but they also nest in Puerto Rico and on islands off
Venezuela and Panama. Extirpated or believed extirpated from Little
Flat Cay (U.S. Virgin Islands) and Montserrat. At sea this species
ranges regularly throughout the western Caribbean and adjacent Atlantic
northward to Cape Hatteras and Bermuda. After storms displaced
individuals may occur over a wider range.
general this larger species replaces the White-tailed Tropicbird from
Puerto Rico southward. The ranges of the two species overlap only from
Puerto Rico to St. Vincent.
Tropicbirds apparently forage over more productive waters than do
White-tailed Tropicbirds. This is a plunge diving species. Feeds on
surface dwelling fishes.
birds breed on cliffs of inhabited islands and on remote cays as a
response to human predation and introduced exotics. Nest in cavities
and rock shelters. Pairs use same nest site each season. Nesting begins
as early as January and continues through spring. Lay a single, heavily
spotted egg. Chicks leave nest by mid summer. No studies conducted on
this species in West Indies partly because of difficult accessibility
of nest sites.
populations are estimated at 1,800 to 3,400 breeding pairs, but
surveys of many of the Lesser Antillean breeding sites are sketchy.
US Virgin Islands
British Virgin Islands
St. Christopher and Nevis
Antigua and Barbuda
St. Vincent and the
declining, but not specifically protected. Considered vulnerable in the
West Indies (Schreiber and Lee 2000). Globally this species should
possibly be considered as Endangered. It is likely that there are
currently fewer than 10,000 pairs when all three subspecies are
tallied. In the Cape Verde Islands, for example, a population reported
to be fewer than 1,000 birds in 1969 had been reduced by fishermen to
fewer than 100 pairs by 1990. Other populations have experienced
colonies need protection from human visitation and systematic control
of exotic animals. The smaller colonies also need protection and to be
a chance to expand (construction of artificial nest sites, etc). All
sites need to be protected from coastal development.
that rats have been shown to be a major problem for White-tailed
Tropicbirds, it can be safely assumed they are for Red-billed
Tropicbirds as well. Many of the extant colonies are on inhabited
islands with shipping ports so Rattus
certainly occurs on these
goats present a problem on Saba and probably other nesting islands,
eating vegetation, stepping in nests, and causing erosion and rock
slides. Also on Saba, extensive rock quarrying operations adjacent to
the major nesting area are causing problems. This mining has already
eliminated many acres of habitat and is threatening adjacent nesting
areas. The Saba population represents the largest breeding population
in the Caribbean.
on the nesting biology of this tropicbird in the West Region are
needed, and, in that a number of nesting sites are on inhabited
islands, it would
be logistically easy to assign series of research projects to
interested graduate students.
R. T. Kimball, S. Reddy, R. C. K. Bowie, E. L Braun, M. J. Braun, J. L.
Chojnowski, W. A. Cox, K. Han, J. Harshman, C. J. Huddleston, B. D.
Marks, K. J. Miglia, W. S. Moore, R. H. Sheldon, D. W. Steadman, C. C.
Witt, T. Yuri. 2008. A Phylogenetic Study of Birds Reveals their
Evolutionary History. Science 320(5884): 1763-1768.
D. D. and
M. Walsh-McGehee. 2000. Population estimates, conservation concerns,
and management of tropicbirds in the Western Atlantic. Caribbean Jour.
Sci. 36(3-4): 267-279.
M. 2000. Status and conservation priorities for White-tailed and
Red-billed Tropicbirds in the West Indies. Pages 31-38 in E.
Schreiber and D. S. Lee (eds.) Status and Conservation of West Indian
Seabirds. Society of Caribbean Ornithology, Special Publication Number
1, 225 pp.
Halewyn, R. and R. Norton. 1984.The status and conservation of seabirds
in the Caribbean. Pages
169-222 in J. P. Croxall, P. G. Evans and R. W.
Schreiber (eds). Status and Conservation of the World’s Seabirds. ICBP
Tech. Publ., No. 2. 778 p.
Indian Breeding Seabird Atlas by Will
Mackin and David Lee is licensed
under a Creative
Commons Attribution-Noncommercial-No Derivative Works 3.0 United States
License. Based on
work at www.wicbirds.net.
Permissions beyond the scope of this license may be available at www.wicbirds.net.
Citation: Lee, D. S., W. A. Mackin. 2008. Red-billed Tropicbird. West Indian
Breeding Seabird Atlas
<http://www.wicbirds.net/rbtr.html>. Last Updated: _____.
Date accessed: ______.