eveis ALBA 



MARCH 1964 to JUNE 1965 







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Figure 24. — Distribution of White Tern. 



May 1964 



Density of birds was high because large 

 numbers of breeding Sooty Terns and Wedge- 

 tailed Shearwaters were in the area. Both were 

 at their annual peak during this month. In 

 addition, Newell's Shearwaters and Bulwer's 

 Petrels were most abundant in May, but alba- 

 tross numbers declined still further and 

 Leach's Storm Petrels and Sooty Shearwaters 

 had nearly finished their northward movement 

 through the area. Increasing numbers of Juan 

 Fernandez Petrels and Black-winged Petrels 

 began to appear in the area as their breeding 

 seasons drew to a close in the Southern Hem- 

 isphere. Two density centers were evident: 

 one within 100 miles of Oahu made up mainly 

 of Sooty Terns and light-phase Wedge-tailed 

 Shearwaters, and one in the southeast corner 

 of the area composed of Sooty Terns, dark- 



phase Wedge-tailed Shearwaters from areas 

 south of the study area, and the newly appeared 

 Juan Fernandez Petrels and Black-winged 

 Petrels. 



June 1964 



Sooty Terns and Wedge-tailed Shearwaters 

 predominated as in May, although their num- 

 bers decreased somewhat. Migrants were ab- 

 sent entirely, as were albatrosses, but the 

 Southern Hemisphere visitors--Juan Fernandez 

 Petrels and Black-winged Petrels--increased 

 somewhat and moved farther north into the 

 study area. Two density centers prevailed 

 again, the one around Oahu mainly of breeding 

 birds, the southern one of Sooty Terns, dark- 

 phase Wedge-tailed Shearwaters, and the south- 

 ern petrels. 



July 1964 



Total density remained unchanged from June. 

 Again, Sooty Terns and Wedge-tailed Shear- 

 waters predominated, the dark-phase birds of 

 the latter attaining their farthest northward 

 range, the southern end of the main Hawaiian 

 islands. Similarly, Juan Fernandez Petrels 

 and Black-winged Petrels moved farther north. 

 The former increased considerably in numbers 

 and was found everywhere except in the north- 

 west corner of the area. 



September 1964 



Total density was slightly reduced from July. 

 Data are not available for August but I assume 

 that density for that month did not differ appre- 

 ciably from the months before and after. The 

 Wedge-tailed Shearwater was the most abun- 

 dant species in September as the birds that 

 bred around Oahu gathered before migrating 

 out of the area. Sooty Terns had already com- 

 pleted their breeding season and were repre- 

 sented by fewer birds, all in the southern half 

 of the study area. Sooty Shearwaters appeared 

 on their southward migration, although not yet 

 in peak numbers. Juan Fernandez Petrels and 

 Black-winged Petrels maintained fairly high 

 numbers and were found throughout the area, 

 although their greatest concentration was still 

 at the southern end. 



October 1964 



Total density increased in October to a fall 

 peak as several species reached peak numbers. 

 Juan Fernandez Petrels and Black-winged 

 Petrels were both abundant, especially in the 



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