• Hydrurga leptonyx;
  • leopard seal;
  • aerial census;
  • age-related spatial distribution;
  • haul-out behavior;
  • wind-chill index


The spatial distribution of leopard seals along the fast-ice edge in the austral spring and summer of 1992 and 1993 in Prydz Bay, Antarctica, was determined by aerial surveys. Fewer individuals were observed within the area, and the seals observed were larger, in 1992 than in 1993. Comparison of the distributions and relative sizes of the seals suggests that there may be an age-related difference in spatial behavior. The greater degree of separation among older seals may be due to intraspecific aggression increasing with age, a hypothesis supported by the high incidence of intraspecific scarring noted on leopard seals in this region. The seals’haul-out behavior was negatively related to wind-chill index.