Recent trends in numbers of four species of penguins at the Prince Edward Islands

  • RJM Crawford
  • PA Whittington
  • L Upfold
  • PG Ryan
  • SL Petersen
  • BM Dyer
  • J Cooper

Abstract

Four species of penguin breed regularly at South Africa’s Prince Edward  Islands: king penguin Aptenodytes patagonicus, gentoo penguin Pygoscelis papua, macaroni penguin Eudyptes chrysolophus and southern rockhopper penguin E. chrysocome. In December 2008, it was  estimated that some 65 000 pairs of king penguins were incubating  eggs at Marion Island, the larger of the two islands in the group, and 2 000 pairs at Prince Edward Island. At Marion Island from 1987 to 2008,  there was no long-term trend in numbers of king penguin chicks that survived to the end of the winter period, but there was considerable fluctuation in chick production in the 1990s. It was roughly estimated that on average 88% of king penguin chicks survived the winter period  (from April to September/October). Numbers of gentoo penguins at Marion Island decreased from more than 1 300 pairs in the mid-1990s to fewer than 800 pairs in 2003, and then increased to almost 1 100  pairs in 2008 as breeding success improved. Between 1994/1995 and  2008/2009, numbers of macaroni and southern rockhopper penguins at Marion Island decreased by about 30% and 70% respectively. In 2008/2009, some 290 000 pairs of macaroni penguins bred at this island, mostly in two large colonies where there was a progressive decrease in the density of nests. At both these colonies, decreases in numbers breeding followed outbreaks of disease. Inadequate breeding success has influenced the decreases of macaroni and rockhopper penguins. In 2008/2009, some 42 000 pairs of southern rockhopper penguins bred at Marion Island and 12 000 pairs of macaroni penguins and 38 000 pairs of southern rockhopper penguins at Prince Edward Island.

Keywords: breeding success; gentoo penguin; king penguin; macaroni penguin; population size; population trend; rockhopper penguin

African Journal of Marine Science 2009, 31(3): 419–426

Author Biographies

RJM Crawford
Marine and Coastal Management, Department of Environmental Affairs, Private Bag X2, Rogge Bay 8012, South Africa; Animal Demography Unit, Department of Zoology, University of Cape Town, Rondebosch 7701, South Africa
PA Whittington
East London Museum, PO Box 11021, Southernwood 5213, South Africa; Department of Zoology, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth 6031, South Africa
L Upfold
Marine and Coastal Management, Department of Environmental Affairs, Private Bag X2, Rogge Bay 8012, South Africa
PG Ryan
Percy FitzPatrick Institute, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch 7701, South Africa
SL Petersen
WWF South Africa, PO Box 50035, Waterfront 8002, South Africa
BM Dyer
Marine and Coastal Management, Department of Environmental Affairs, Private Bag X2, Rogge Bay 8012, South Africa
J Cooper
Animal Demography Unit, Department of Zoology, University of Cape Town, Rondebosch 7701, South Africa
Section
Articles

Journal Identifiers


eISSN: 1814-2338
print ISSN: 1814-232X