Article

Seasonal occurrence and diet of leopard seals (Hydrurga leptonyx) at Bird Island, South Georgia

Antarctic Science (Impact Factor: 1.63). 02/1998; 10(01):75 - 81. DOI: 10.1017/S0954102098000108

ABSTRACT Seasonal haul-out patterns and diet of individually marked leopard seals (Hydrurga
leptonyx) were investigated at Bird Island, South Georgia during the 1983–96 winters. A total of 2956 leopard seal sightings were made, and 121 seals were tagged during the study, mainly between 1993 and 1996. Photographs of scars and pelage patterns were also used to identify a subset of these individuals across years, which provided no evidence of tag loss between or within years. Leopard seals were observed between April and November; the mean time between the first and last sightings in each year was 208 d (s d ± 48). Between 1993–96, eight seals were resident around the island for more than 100 d, and the longest recorded residence was 130 d. The proportion of tagged seals resighted was 0.35 and 0.17 in 1995 and 1996 respectively. Based on estimates of body length, <5% of the seals were juveniles (0–1 years) and >70% were not sexually mature. There was considerable inter-annual variation in abundance, with a maximum of 502 sightings during 1994, compared with a minimum of 21 during 1986 and 1989. Antarctic fur seals (Arctocephalus
gazella) were the main prey item (58% of kills observed and 53% of scats). Other items included penguins (28% of kills observed and 20% of scats) and fish (24% of scats). Antarctic krill (Euphausia
superba), southern elephant seals (Mirounga
leonina) and seabirds other than penguins were also present in the diet in small quantities.

2 Bookmarks
 · 
1,340 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Data on the timing of pupping by the three species of phocid that breed on the Antarctic pack-ice (crabeater, Ross and leopard seals) are limited. Better information would improve our understanding of these species'' population and reproductive ecologies, and could facilitate planning and design of population surveys. Observations of the presence or absence of pups with adults during numerous voyages of the Australian National Antarctic Research Expeditions to East Antarctica during spring and early summer months are analysed and presented. The earliest sighting in any year of a crabeater pup accompanied by an adult was on 2 October and the latest sighting on 15 December. The ratio of crabeater pups to adults increased rapidly during the 10-day period 16–25 October, implying a pulse of births over this time. Ross seal pups with an accompanying adult were sighted between 24 October and 22 November, with a peak in the pup-adult ratio occurring in the period 6–15 November. Leopard seal pups were sighted between 8 November and 25 December, with the pup-adult ratio relatively constant during this period. The data provide circumstantial evidence that the maximum durations of lactation reported in the literature for the three species may be over-estimates. If lactation is shorter than reported, asynchrony in the timing of pupping, either among or within years, is implied.
    Polar Biology 09/2003; 26(10):648-652. · 2.01 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The diet of male and female leopard seals (Hydrurga leptonyx) was investigated in Prydz Bay, Eastern Antarctica. A total of 70 scats, 1 regurgitate and 3 stomach contents were collected, during the austral summer, between November 1999 and March 2002. Eight prey species were identified, including birds, mammals, fish and invertebrates. Adelie penguins (Pygoscelis adeliae) were the main prey item and crabeater seals (Lobodon carcinophagus), benthic and pelagic fish, amphipods and krill were found to supplement the diet. Cephalopods did not occur in the diet. Crabeater seals were still being captured well after weaning, and were found in the diet of both male and female leopard seals.
    Polar Biology 01/2004; 27(12):729-734. · 2.01 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: A total of 14 scats of the Leopard Seal were collected on ice floes close to Cierva Point, Danco Coast, Antarctic Peninsula, during February and March 2000. Krill was the most frequent and numerous prey and also constituted the bulk of the diet; penguins and fish followed in importance by mass. Among fish, Gobionotothen gibberifrons was the most frequent prey and also predominated by mass whereas the myctophid Gymnoscopelus nicholsi was the most numerous prey. The results are compared with previous studies and the differences in the composition of the diet observed among the Leopard Seal and other seals at the study area are discussed.
    Polar Biology 01/2009; 32(2):307-310. · 2.01 Impact Factor

Full-text

View
210 Downloads
Available from
May 20, 2014