_Scaeophaethon rubricauda rothschildi_ Mathews, Birds Australia, 4,
1915, p. 303. (Type locality, Laysan and Niihau.)
_Phaeton rubricaudus_ Finsch, Journ. f. Ornith., 1880, p. 296
(Carolines); _idem_, Ibis, 1881, p. 115 (Ponapé).
_Phaeton rubricauda_ Finsch, Proc. Zool. Soc. London, 1880, p. 577
(Ruk); Wiglesworth, Abhandl. und Ber. Zool. Mus. Dresden, no. 6,
1890-1891 (1891), p. 73 (Ruk, Ponapé, Marshalls).
_Phaeton rubricauda_ Ogilvie-Grant, Cat. Birds British Mus., 26,
1898, p. 451 (Caroline Islands); Hartert, Novit. Zool., 7, 1900,
p. 11 (Ruk); Hand-list Japanese Birds, rev., 1932, p. 187 (Pagan,
Truk, Ponapé, Marshalls).
_Scaeophaethon rubricauda_ Kuroda, in Momiyama, Birds Micronesia,
1922, p. 34 (Mariannes, Ruk, Ponapé, Marshalls).
_Phaethon rubricauda rothschildi_ Yamashina, Tori, 7, 1932, p. 406
(Pagan); _idem_, Tori, 10, 1940, p. 676 (Maug).
_Phaethon rubricaudus rothschildi_ Hand-list Japanese Birds, 3d
ed., 1942, p. 209 (Maug, Pagan, Truk, Ponapé, Marshalls).
_Geographic range._--Bonin and Hawaiian islands south to
Micronesia. In Micronesia: Mariana Islands--Maug, Pagan; Caroline
Islands--Truk, Ponapé; Marshall Islands--exact locality unknown.
_Characters._--Adult: Long-tailed sea bird white with pinkish tint
except for black lores and eye streak; black shafts on feathers of
secondaries, flanks, and tail coverts; black bases on feathers of
head; central tail feathers elongate with black shafts and bright
red webs; bill orange-red with black nasal streak; tarsus and foot
bluish-yellow, distal part blackish. Immature: Resembles adult but
barred with black above; bill blackish.
_Measurements._--Yamashina (1940:676) lists the measurements for
seven adult birds from Maug in the northern Marianas as wing
304-319 and exposed culmen 55-62.
_Nesting._--Yamashina (1932a:406) reports the taking of one egg at
Pagan in the Marianas on February 15, 1931.
_Remarks._--The Red-tailed Tropic Bird has been recorded from the
Mariana, Caroline, and Marshall Islands. On the basis of our present
knowledge it appears to be uncommon in most of Micronesia and may be
established as a resident bird only in the northern Marianas, as shown
by Yamashina (1932a:406 and 1940:676), Coultas obtained an immature male
at 3° N and 158° E, which is at a point in the ocean south of the
eastern Carolines. Possibly this bird and others obtained in the
Carolines are representatives of the subspecies, _P. r. melanorhynchos_
Gmelin, which is known from the Palmerston, Society and Turtle islands.
=Phaëthon lepturus dorotheae= Mathews