Penguins and purse-seiners : competition or co-existence?
Master Thesis
1985
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University of Cape Town
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Abstract
The relationships between the pelagic purse-seine fishery and Jackass penguins (Spheniscus demersus) were investigated at Saldanha Bay, on the south-western coast of South Africa, between December 1982 and August 1983. The distribution at sea and the foraging behaviour of Jackass Penguins were examined by running standard transects with a sail boat in waters close to the birds' breeding islands. The use of a sail boat permitted close observation of foraging penguins with minimal disturbance. Penguin numbers at sea were lowest in December, when birds were confined to the breeding islands during moulting and were high in March and July during breeding peaks. While most penguin group sizes were small (one or two birds), over 44 % of penguins occurred in groups of more than 10 birds. Three stereotypic penguin group formations occurred: 'facing-search', 'line-abreast', and 'pointed-ovoid'. Penguins also foraged in association with other sea birds and marine mammals.
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Bibliography: leaves 110-124.
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Reference:
Broni, S. 1985. Penguins and purse-seiners : competition or co-existence?. University of Cape Town.