_Remarks._--Birds taken in Micronesia differ only slightly from those from other areas in Oceania. Within Micronesia (see table 15) the birds from the Palaus have the shortest wing and shortest exposed culmen. The White-tailed Tropic Bird appears more numerously in western and northern Micronesia than in the Marshall Islands. This distribution may be correlated with a preference for the "high" islands; especially those which have rocky cliffs, including Guam, Rota, Peleliu, Angaur, and Truk. Reports were received in 1945 that the birds were only infrequently seen at Ulithi, a low atoll. Stott (1947:524) observed birds flying into rocky crevices at Saipan on December 18. Gleise (1945:221) also recorded the bird in the vicinity of Saipan. Borror (1947:416) reports seeing birds at Agrigan on July 29, August 5 and 6, 1945. Coultas (field notes) found tropic birds common at Ponapé in November and December, 1930, in forested regions and along the cliffs. He made similar observations at Kusaie and Palau. At Ponapé and Palau, Coultas noted the use of the eggs, young and adults as food by the natives. At Palau the plumes are used in headdresses worn by the natives, the birds being taken with the blowgun. Murphy (1936:807) states that the principal enemy of the White-tailed Tropic Bird at Bermuda is the introduced rat (_Rattus rattus_). Introduced rats, particularly _Rattus mindanensis_ on Guam, may prey on the nesting birds. Baker (1946c:404) writes that this rat is a good climber and may spend considerable time in trees. The rat was trapped also in rough coral jungle at the edge of the cliffs, where tropic birds, Micronesian Starlings and other species, may have been nesting. Little has been recorded concerning the post-breeding season wanderings of these tropic birds in Micronesia. They seemingly spend considerable time at sea, but whether they move as far from their breeding areas as do birds in the Atlantic, as reported by Murphy (1936:803), Baker (1947a:253) and others, is not known. Murphy (1936:796) notes that the northward distribution of the tropic birds in the Atlantic is dependent on the warm currents of water. In the western Atlantic, the poleward-flowing, warm currents of the Gulf Stream allow for the northern extension of the range of these birds to Bermuda. In the eastern Atlantic, cool currents flowing toward the equator restrict the northern range. The same condition prevails in the eastern Pacific where warm current flowing toward the pole enable the birds to range north to the Bonins and other islands.