SUMMER SEABIRD DISTRIBUTIONS IN DRAKE PASSAGE, THE CHILEAN FJORDS AND OFF SOUTHERN SOUTH AMERICA

Abstract

SummaryThe paper summarizes observations on the pelagic distributions of sea‐birds in Drake Passage and off southern South America, collected by ship‐borne observers between December 1969 and April 1970, and in March and April 1972. The birds' distributions have been related to sea surface temperatures and, in the case of the Chilean fjords, to water types defined in terms of temperature and salinity; a partial attempt has been made to relate them to the distribution of the macroplankton.The boundary between the ranges of Phalacrocorax albiventer and P. atriceps in the Chilean fjords is much farther west than previously reported, and there is some evidence that it has moved westwards within the last 20 years. It is suggested that its position is determined by oceanographic rather than climatic factors.A sighting of Pterodroma macroptera in Cockburn Channel is the first record of this species for Chile. Exceptionally southerly records of Lobipes lobatus in Magellan Strait, and Pterodroma mollis south of the Antarctic Convergence are also described. An apparent decline in the numbers of Pterodroma neglecta at Masatierra, Juan Fernandez, is noted.