Aggressive and maternal activities of female southern elephant seals (Mirounga leonina)

Abstract

The aggressive and maternal behaviours of 44 individually marked female southern elephant seals, Mirounga leonina, were studied at South Georgia. Evidence of dominance and subordination could be determined in only 29% of 1315 encounters, but dominance-subordination relationships were observed in 49% of known cow dyads. Status was not necessarily size- or age-related, but most young, small cows were of low status. High-status cows reared larger pups which were bitten less frequently than pups of low-status cows. Orphaned pups were bitten at least three times as frequently as pups with mothers. Cows with pups initiated more interactions than pregnant cows, and were dominant more frequently. Older cows responded to their newborn pup more rapidly and intensively than did younger cows and this difference can be important in crowded breeding assemblies. Cow and pup behaviour in M. leonina at South Georgia is compared with that of M. angustirostris in California. The main differences are thought to relate to differences in population density.