HIGH WINTERTIME MORTALITY-RATE IN A POPULATION OF CORSICAN MOUFLONS (OVIS-MUSIMON) IN THE SUB-ARCTIC ARCHIPELAGO OF KERGUELEN

The population of Corsican mouflon (Ovis musimon) introduced onto the Kerguelen archipelago shows periodic winter die-offs, at most every five years. This paper investigates the mortality occurring in 1988, when at least 289 individuals died. Over 60% of the carcasses were recovered from caves located at the bottom of cliffs. These shelters are regularly used by the mouflons. This allows them to reduce their energetic expenditure in such a harsh, subantarctic climate. A high proportion of lambs died during the winter crash. Among yearlings and adults, males showed a much higher level of mortality than females. Such a sex-biased mortality is of prime importance for the dynamics of the population. After the crash, the population structure became strongly biased, with a sex-ratio of 10 females to each male.