Dispersal and dispersion of southern elephant seals in the Kerguelen province, Southern Ocean Article - Juillet 2011

W. Chris Oosthuizen, Marthan N. Bester, Cheryl A. Tosh, Christophe Guinet, Dominique Besson, P.J. Nico de Bruyn

W. Chris Oosthuizen, Marthan N. Bester, Cheryl A. Tosh, Christophe Guinet, Dominique Besson, P.J. Nico de Bruyn, « Dispersal and dispersion of southern elephant seals in the Kerguelen province, Southern Ocean  », Antarctic Science, juillet 2011, pp. 567-577. ISSN 0954-1020

Abstract

Southern elephant seals Mirounga leonina within the Kerguelen province disperse between Marion Island (MI), Iles Crozet (IC) and Iles Kerguelen (IK) despite the high site fidelity characteristic of this species. From 1987-2002, 199 IC individuals, or 11.63% of the tagged population there, were resighted at MI. Resights of IC seals at MI peaked during the juvenile moult and seals aged 0-2 represent 66% of all resights made. Equal numbers of male and female seals (all age classes) were dispersing. Dispersing breeding females (n522, on 33 occasions) outnumbered dispersing breeding males (n56, on 16 occasions), after initially emigrating from IC to MI as juvenile seals (natal dispersal). Greater male-mediated gene flow was ultimately attained due to the polygynous mating system and some extremely successful males. Of 132 seals fitted with satellite-relay data loggers at MI, six hauled out at IC and three at IK. Two of the seals which migrated to IC were born at MI ; all others were unmarked males likely to be native to IC or IK. Dispersal should ideally be considered when assessing vital rates for southern Indian Ocean elephant seal populations.

Voir la notice complète sur HAL

Actualités