A similar effect has been shown for the Galapagos fur seal (Arctocephalus galapagoensis) (Trillmich and Limberger, 1985). This species is quite dimorphic. Females weigh about 30 kg, territorial males about 65-70 kg. During El Niño high adult mortality (30% in females and about 100% in reproductive males) and extreme juvenile mortality (complete loss of the 1982, 1981, and 1980 cohort) was coupled with hardly any production of young in 1983, immediately after the event. 

   What was most surprising in this species was the almost total mortality of males that had been territorial in the 1982 El Niño while females survived much better. Territorial males fast during their two to six weeks on territory. The males that did so in 1982 returned to an ocean that provided hardly any food, and they starved to death. Females never fast for so long and their absolute food requirements are about half of those of fully grown males. Presumably due to this difference in foraging regime and food needs, females survived in El Niño much better than territorial males, even though almost all of the surviving females were unable to produce a pup in the 1983 reproductive season (Trillmich and Limberger, 1985) showing that they could not accrue sufficient resources for successful reproduction late in the El Niño. These data show that in sexually dimorphic species the sexes can react quite differently to the effects of an environmental disturbance, as if they belonged to different species.