Populations of Surface-nesting Seabirds at Marion Island, 1994/95–2002/03

Abstract

During the 1990s and early 2000s, populations of surface-nesting seabirds at Marion Island showed different trends, but for the majority of species numbers decreased. Reduced numbers of gentoo penguins Pygoscelis papua, eastern rockhopper penguins Eudyptes chrysocome filholi, Crozet shags Phalacrocorax [atriceps] melanogenis and probably macaroni penguins E. chrysolophus are most plausibly attributed to an altered availability of food. Decreases in numbers of dark-mantled sooty albatrosses Phoebetria fusca, light-mantled sooty albatrosses P. palpebrata, southern giant petrels Macronectes giganteus and possibly northern giant petrels M. halli may have resulted from mortality of birds in longline fisheries. However, populations of wandering Diomedea exulans and grey-headed Thalassarche chrysostoma albatrosses fluctuated around a stable level. Numbers of Subantarctic skuas Catharacta antarctica and kelp gulls Larus dominicanus breeding at Marion Island also decreased. Kerguelen Sterna virgata and Antarctic S. vittata terns remain scarce at the island. Trends for king penguins Aptenodytes patagonicus were not reliably gauged, but numbers probably remained stable or increased. There were large fluctuations in numbers of king penguin chicks surviving to the end of winter.

Counts of Surface-nesting Seabirds Breeding at Prince Edward Island, Summer 2001/02

“…Populations of Crozet shags and Kerguelen terns, both localized endemics to the Kerguelen Province, have decreased to less than half the numbers counted in 1984 Hunter 1985, Ryan 1987). In the case of the tern, this corresponds with an increase in the population on Marion Island (Ryan 1987, Crawford et al 2003c, and thus there may not be cause for concern. The apparent switch to Marion Island is surprising given the importance of terrestrial invertebrates in the diet of this species (Stahl and Weimerskirch 1981) and the adverse impact that introduced house mice Mus musculus have had on invertebrate populations on Marion Island (Huyser et al 2000).…”

Population development and historical occurrence of king penguins at the Falkland Islands

“…In recent years, king penguin numbers have increased throughout most of their range (Van den Hoff et al 1993, Williams 1995, Woehler et al 2001, Crawford et al 2003, Weimerskirch et al 2003, Delord et al 2004, Van den Hoff et al 2009, after more than a century of decline as a result of exploitation for penguin oil (Williams 1995). In the absence of supporting evidence (as discussed below), a similar history has tenuously been claimed for the Falklands population, which was reportedly subjected to exploitation during the 1800s with total extermination by 1870 (Williams 1995, Woods & Woods 1997, Clausen & Huin 2003.…”

“…The world population of king penguins (Aptenodytes patagonicus Miller) numbers c. 1.6 million breeding pairs, and they are particularly numerous in the Indian Ocean (Woehler & Poncet 1993, Crawford et al 2003, Delord et al 2004, Bost et al 2011. In the Atlantic Ocean the bulk of the population, over 450 000 breeding pairs, is situated at South Georgia (Poncet 2006), with only a small colony breeding at the Falkland Islands (Clausen & Huin 2003).…”

Multiple occurrences of king penguin (Aptenodytes patagonicus) sexual harassment by Antarctic fur seals (Arctocephalus gazella)

“…Funk and Trypot beaches are small AFS breeding colonies (<100 pups born annually), while Goodhope Bay is a bachelors beach with young and sub-adult males only. Goodhope Bay and Funk beaches have small (<900 breeding pairs) and very small (<150 breeding pairs) KP colonies respectively (Crawford et al 2003), while Trypot beach is home to a small colony of moulting and resting birds.…”