The fitness of dispersing spotted hyaena sons is influenced by maternal social status

Life history theory predicts that mothers should provide their offspring with a privileged upbringing if this enhances their offspring ’ s and their own fi tness. In many mammals, highranking mothers provide their offspring with a privileged upbringing. Whether dispersing sons gain fi tness benefi ts during adulthood from such privileges (a ‘ silver spoon ’ effect) has rarely been examined. In this paper, we show that in the complex, female-dominated society of spotted hyaenas, high-born sons grew at higher rates, were more likely to disperse to clans offering the best fi tness prospects, started reproducing earlier and had a higher reproductive value than did lower-born sons. This illustrates the evolutionary importance of maternal effects even in societies in which male size or fi ghting ability does not infl uence fi tness. By demonstrating for the fi rst time in a non-human mammal that maternal status infl uences immigration patterns, the study also advances our understanding of two key ecological and evolutionary processes, dispersal and habitat selection.