In view of theoretical interest in the relationships between mating systems and dispersal patterns and the paucity of empirical data on dispersal in monogamous mammals, I studied natal dispersal in the monogamous rodent Peromyscus californicus. Genealogical relationships were determined using fluorescent pigment transfer and DNA fingerprinting, and dispersal distances were determined using dispersal fences and intensive trapping. Minimum dispersal distances were greater for females than for males. Philopatric males (those settling within one home-range diameter of their birth site) tended to be from smaller litters than non-philopatric males. Minimum dispersal distances of males were positively associated with natal litter size at weaning, whereas minimum dispersal distances of females were positively associated with number of sisters in the natal litter. These results suggest that intrasexual mate competition drives female dispersal, while resource competition drives male dispersal. Males remain closer to their natal range than females, most likely to acquire and defend resources to attract females. Peromyscus californicus is unusual among mammals in displaying both a monogamous mating system and female-biased dispersal.
Ribble, D.O. 1992. Dispersal in a monogamous rodent, Peromyscus californicus. Ecology 73:859-866.