Relative success of residents and immigrants in Peromyscus leucopus

The relative success of a sample of 99 immigrant dispersers was studied in a population of Peromyscus leucopus in deciduous forest from 1980 to 1985. Dispersers were identified in two ways; (1) as immigrants to a natural dispersal sink and (2) as individuals that relocated their center of activity more than one home range diameter within a large live-trapping system. Female immigrants were significantly less likely to be pregnant or lactating than philopatric residents; males showed no significant difference. Reproductive immigrants were more likely than non-reproductive immigrants to establish residency after dispersal. There was no difference in survivorship of philopatrie residents and those dispersers that successfully immigrated.