A multivariate analysis of phenotype and paternity in male harbor seals, Phoca vitulina, at Sable Island, Nova Scotia

Abstract

Understanding the links between phenotype and reproductive success is critical to the study of the evolution of mating systems and life-history patterns. We examined the relationship between phenotype and mating success of male harbor seals (Phoca vitulina concolour) at Sable Island, Canada. Cluster analyses of eight traits including mating success determined by genetic paternity analysis, haul-out behavior, body mass, and mass change identified four groups of males with distinct characteristics. The most successful males were of moderate body size, were rarely sighted alone, were associated with many different groups on shore, and were sighted on the haul-out relatively infrequently. Large males that hauled out frequently alone, previously thought to be socially dominant, were less likely to be successful. Also less successful were smaller, younger males. Contrary to our hypotheses, and unlike most terrestrially breeding pinnipeds, body size and reproductive effort were not positively associated with mating success, and some successful males appeared to spend considerable time foraging in deep water.