The influence of maternal quality and social environment on male dispersal behaviour, alternative reproductive tactics and glucocorticoid levels in a free-ranging social mammal

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In most social mammals, most males leave their natal group and disperse to another group to reproduce. The behaviour that a male expresses during dispersal and the tactics it applies to reproduce are of fundamental importance because they strongly influence male fitness. In many species, males vary in their dispersal behaviour and reproductive tactics, but little is known about the factors that cause this variation. Recent theoretical studies suggest that the maternal quality and social environment that a male experiences during development may shape its dispersal behaviour and reproductive tactics by influencing its condition, its ability to cope with stressful situations, and its release of ‘stress’ hormones. Here I propose to test predictions on the influence of the maternal and social environment on male dispersal behaviour, reproductive tactics, and basal faecal glucocorticoid concentrations in a large social carnivore, the spotted hyena. Tests will be based on data from natural experiments, detailed behavioural observations, long-term demographic data, and faecal samples collected non-invasively from a well-studied population of several hundred hyenas in Tanzania. The results from the proposed study will allow us to better assess the extent of maternal effects on key behavioural and life-history traits of adult males, and increase our understanding of the variation in reproductive tactics of males and their ability to choose and settle in high-quality breeding sites.