EAC 5, Shearwater, March 1967
Page 278
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Transcription
all the black storm petrels noted this cruise were probably Leach's. Density distribution was noticeably different in the north section where on previous cruises it has not exceeded .032 birds per square mile. This survey a density of .113 (N=28) was noted in the north. A brief review of regional density suggests that the Leach's petrel probably moves around a great deal in the winter range. Besides the fluctuations noted above, the central area has varied from .106 to .199 b/sq.mi. and the south from .153 to .308. East- west densities have also varied considerably. As noted in previous reports, some of this variation may be accounted for by differences in observation conditions. Six Leach's Petrels were collected in the grid; of four males two were recorded as having enlarged gonads, and one of two females had slightly enlarged ova. Fork-tailed Petrel (Oceanodroma furcata) 2 Both sightings were in the north section. In view of previous survey results it does not seem reasonable to assume that the apparent population decline is significant. Pterodroma sp. (Unidentified) 7 Of seven sightings, six (two birds each in three sightings) were noted in the western half of the grid. Only two were seen reasonably well, and these were believed to have been White-winged Petrels (P. leucoptera), but a positive field identification was not made. Red Phalarope (Phalaropus fulicarius) 291 + 4 nocturnal Red Phalarope were the most abundant species in the grid during this cruise. Most were in flocks, but many were also recorded