TABLE 5 



Geographic Distribution of Flocks. "No. Birds" refers to the number of each species present in all 



feeding (locks of each region. Species are arranged according to their overall relative abundance in all 



feedinc flocks. No flocks were seen in Regions V-VI1. 



Species 



Region 



111 



IV 



Flocks 



No. 

 Birds 



Flocks 



No. 

 Buds 



Flocks 



No. 

 Birds 



Flocks 



No. 

 Birds 



Sooty tern 

 Noddy sp. 



Wedge-tailed shearwater 

 Brown noddy 

 White tern 

 Red-footed booby 

 Great frigatebird 

 White-tailed tropicbird 

 Masked booby 

 South polar skua 

 Stercorariid sp. 

 Audubon's shearwater 

 Bulwer's petrel 

 Kermadec petrel 

 "Shearwater/petrel" 



85 



Totals 



85 



1 .095 



239 



651 



Pratt el al., 1987). They have not been previously recorded 

 from the Gilbert Islands (Amerson, 1969). Our records are as 

 follows: 



Line Islands . Single birds were seen on 15 September at 

 10°38'N. 156°16'W; 10°13'N. 156°19'W (Hying north): 

 09°29'N. 156°26"W (with 2 Bulwer's petrels); 16Septemberat 

 06°16'N. 156°50'W (flying north): 04°55'N. 157°00'W (flying 

 south): and on 19 September at 00°22'S. 156°37'W. 



Phoenix Islands . All single birds flying south, as follows: 

 2 October at 06°29'S, 162°19'W; 3 October at 05°16'S. 

 166 o 53'Wand05 o 12'S. 167°06'W. 



Gilbert Islands . One bird flying southeast on 7 October at 

 00°49'S. 179°10'E. 



We observed 12 adults (10 on transect) between 

 15 September and 7 October 1988. Two had particularly pale 

 plumage. Sightings occurred just north of and within the 

 Northern Line Group, where densities were highest 

 (0.13/10 km 2 ), in the Phoenix Group, and east of the Gilbert 

 Islands. Of seven birds flying in a direct compass direction, 

 four from the Line and Phoenix Islands were flying south, and 

 one from the Gilbert Islands was flying southeast. Thus 71% 

 of individuals of this species were flying in the approximate 

 direction of their New Zealand breeding grounds, when such 

 movements are expected. Only one Cook" s petrel was associated 

 with other birds (two Bulwer's petrels). 



Stejneger's Petrel {PterodromalonvirostrisY . We observed 

 two adult Stejneger's petrels in the Northern Line Group 



(05°56'N, 156°53'W; 06°24'N. 156°50'W) on 16 September 

 1988, about 170 km east of Palmyra Atoll. There are few 

 central Pacific records; POBSP personnel saw some near the 

 Phoenix Islands (King. 1967). although this is not mapped in 

 Harrison ( 1985). There appear to be no records of Stejneger's 

 petrel between Hawaii and the Phoenix Islands. 



Additional sightings were made during the ICBP 1990 

 Line and Phoenix Islands Expedition (ICBP. 1990; Kepler, 

 1990). We observed no Stejneger's petrels in the Line Islands 

 during March and April but saw several birds heading north in 

 the same area during May ( 1 1° to 15°S, 149° to 15 1°W). 



Bulwer's Petrel (Bulweria hulueri) : This species was 

 relatively common ( N = 27 ) throughout the four regions of the 

 Pacific covered by the cruise. Because of its small size, it was 

 only counted within 1 00 m of the ship ( see Methods). Since this 

 species breeds and ranges at widely-scattered locations in the 

 Central and western Pacific, all our observations fell within its 

 expected range. Regions I through IV. Three-quarters of our 

 sightings were in Micronesia, primarily south of Kosrae and 

 north of Ulithi Atoll. None were seen west of Yap (139°E). 

 The major Bulwer's petrel breeding grounds in the northwest 

 Pacific (Bonin, Volcano, islands of Taiwan and China) are well 

 north of Micronesia, and Bulwer's petrel is regarded as a 

 species whose numbers decrease gradually with increasing 

 distance from land ( King, 1970). Breeding occurs from April 

 to September (King, 1967). Of our early October birds, equal 

 numbers were heading either north or south. 



233 



