The overall density of Bulwer's petrel in Micronesia was 

 0.80/10 km 2 , lour times the density encountered in Regions I 

 through III (Line. Phoenix and Gilbert Islandsi. 



Streaked Shearwater (CalonectrisleucomelusY . This large 

 shearwater breeds on coastal islands off China, Japan and 

 Korea and is known to travel southward during October and 

 November toward its main wintering area in the New Guinea- 

 northern Australia area. We observed six individuals, all from 

 18-20 October in the far western Pacific close to the Philippines 

 (Region V). Two were recorded as having darker plumage. 

 Sightings were restricted to a very narrow band of ocean 

 between 130°15'and 1 35° 14'E longitude. These were probably 

 postbreeding migrants: three ( 50% ) were flying due south, and 

 all were solitary. 



Flesh-footed Shearwater (Puft'iniis carncipes) : Flesh- 

 footed shearwaters breed during the austral summer on islands 

 off Australia and New Zealand, and winter in the North Pacific 

 north of the subtropical convergence. We observed four flesh- 

 footed shearwaters in Regions I. II and IV. all migrating birds 

 returning to the south temperate Pacific to breed. Two were in 

 the central Pacific south of Hawaii and in the Phoenix Islands, 

 where the species has been reported in very small but regular 

 numbers during the migration months. October to April ( King, 

 1967). The rest occurred in a more expected sector of the 

 western Pacific, although in a relatively narrow swath (05° 1 2'S 

 to 03°59'N, 164°08'E to 163°46'E), viz. between the western 

 Gilbert and far eastern Caroline Islands. The densities of these 

 transequatorial migrants were equal throughout (0.03/ 10 knr). 



Wedge-tailed Shearwater ( Pitffimts pucitlcus ) : The wedge- 

 tailed shearwater has long been considered the most common 

 widespread shearwater of the southwest Pacific (Mayr, 1945; 

 Jenkins, 1979). This species accounted for 8% of our total 

 sightings (Fig. 4). It breeds on numerous islands throughout 

 most of the tropical and subtropical Pacific from eastern 

 Australia to Mexico south to the Pitcairn Islands. We observed 

 293 individuals, 213 (73%) of which occurred in Micronesia. 

 The two largest concentrations, of 150 and 22 birds, both 

 occurred on 13 October near Pohnpei. Our sightings ranged 

 from immediately south of Hawaii through the Line. Phoenix, 

 and Gilbert Islands, Micronesia, and the Philippine Islands to 

 the far western edge of its range at 121°28'E longitude. 



Although the pelagic distribution of this species is well 

 known for the central and eastern Pacific regions and Marshall 

 Islands (King, 1967. 1970. 1974b; Amerson, 1969), observations 

 are surprisingly scarce in the Carolines-Belau-Philippine region 

 ( King, I974b;63. 93). For this reason, we discuss our records 

 in waters west of 180' longitude (Table 6). where 84' i 

 (N = 245) of our wedge-tail sightings occurred: 



a) Gilbert Islands (Region III. IS0-165°E). Although 

 wedge-tailed shearwaters are known from this area ( I larrison, 

 19X5). we have been unable to find records of specific sightings 

 in a detailed summary of published data on wedge-tailed 

 shearwater distribution (King, 1974b). They are not listed, 

 even as visitors, in the Gilbert Islands by Pratt el id. ( 1987) or 

 Amerson ( 1969). 



Fig. 4. Relative abundance of species or species groups on the cruise track of 

 the R/V Akademik Korolev. Total number of birds seen was 3.6hS. 

 belonging to 1 1 different families. 



Although a resident breeder on several of the northern 

 Marshall Islands (Amerson, 1969), the closest recorded sightings 

 to the Gilbert Islands are 10 dark-phase birds seen on 

 2 November 1960 at Jaluit Atoll, southern Marshall Islands 

 (Morzer Bruyns, 1965:58) and between 04°00' and 02°30'S, 

 169-155°E in October 1951 southwest of the Gilberts between 

 Niutao Atoll and the Admiralty Islands ( Mac Donald & Lawford, 

 1954). These latter birds were reported as possibly P. came i pes. 

 which has a totally different flight pattern. Our nine sightings 

 were close to the equator at 179°E longitude, approximately 

 300 km north-northeast of Arorae Island. All birds were flying 

 south. 



b) Micronesia (Region IV, 165-136°E). Although known 

 to be resident breeders in the northern Marshall Islands 

 ( Amerson, 1 969:295 ) and central Carolines ( Murphy. 1951:9), 

 pelagic records of wedge-tails are sparse (King. 1974b:93). 

 Breeding colonies are also difficult to locate. Prattefa/. ( 1987) 

 state that this species is rare in western Micronesia: the 

 westernmost record at these latitudes i s evidently 1 50°E ( District 

 ofTruk). 



We observed wedge-tailed shearwaters (N = 213) 

 throughout the Caroline chain of islands east to I32°59'E 

 longitude: 73' ; of wedge-tails observed on our cruise were in 

 this region. 



c) Philippine Sea and Basin (Region V. 136-125 Fl. Of 

 21 wedge-tailed shearwaters seen west of 150°E (east of the 

 Philippines and ca. 450 km north of Belau). all were dark phase 

 (Table 6). Those in direct flight were heading either south or 

 west. This species mas visit Belau more frequently than 

 records indicate. ( )w en ( 197 1 ) does not mention its occurrence, 

 although Pratt ei id. listed it as a visitor. The overall density of 



234 



