Air census of two colonies of Adelie Penguins (Pygoscelis adeliae)in Ross Dependency, Antarctica

Abstract

Air photographs taken on biological survey flights between 1962 and 1965 have yielded counts of Adelie Penguin breeding colonies at Beaufort Island in the southwestern Ross Sea and Inexpressible Island on the Victoria Land coast (Fig 1). These colonies are remote from expedition bases, seldom visited, and too large for accurate assessment from the ground. Earlier estimates of their size are summarised by Taylor (1964). Methods of estimating colony size are discussed by Caughley (1960) and Taylor (1962). This survey is based on serial black and white photographs taken at optimal times of the breeding cycle; counts are converted to estimates of breeding population size using data from a ground study at the Cape Royds (Fig 1) breeding colony and from known patterns of breeding at other colonies (Sladen, 1958; SapinJaloustre, 1960; Taylor. 1962; Stonehouse. 1963; Reid. 1964).