Agonistic Encounters Among Male Elephant Seals: Frequency, Context, and the Role of Female Preference

SYNOPSIS. Aggressive interactions between male northern elephantseals, Mirounga angustirostris, observed during the course ofthree breeding seasons are analyzed from the perspective ofcosts and benefits to individuals. Males spend less than onepercent of their time in aggressive activities and the overwhelmingmajority of agonistic interactions consist only of visual andvocal threats rather than physical combat. Males are most likelyto threaten other males when the likelihood that they will besuccessful in displacing the opponent is high. Males who aremounting females, or who are in close proximity to females,are threatened more frequently than males who are otherwiseoccupied. However, high ranking bulls do regularly issue threatswhich are not provoked by the location or behavior of the recipient.Despite the obvious costs of such threats, this behavior maybe favored as a result of female choice. Estrous females aremore receptive when mounted by a male who has just dominatedanother than when mounted by a male of similar rank who hasbeen resting or recently displaced by a stillmore dominant male. A general argument is made that in species where social statusof males is correlated with their genetic fitness, female choiceis likely to be based on social signals which are used incompetitionbetween males.