The effects of mating on infanticide and pup discrimination in white-footed mice

Summary A laboratory study was conducted with white-footed mice (Peromyscus leucopus) to determine (1) if cohabitation and/or successful mating inhibits infanticide, and if so for how long, and (2) if males and females can discriminate between their own (familiar) and strange (unfamiliar) pups. Infanticidal males and females that were paired for 15 days and did not reproduce were not inhibited from killing pups, whereas infanticidal males and females that were paired until they reproduced were inhibited from committing infanticide at 4 days postpartum. Neither males nor females discriminated between familiar and unfamiliar pups with regard to engaging in infanticide. Approximately 50% of wild-caught males and females killed pups in the laboratory. Infanticidal pairs bred significantly sooner than did noninfanticidal pairs. The results are consistent with the promiscuous nature of P. leucopus males and territoriality of P. leucopus females. Offprint requests to: Donna M. Cicirello, Kellogg Biological Station, 3700 E. Gull Lake Drive, Hickory Corners, MI 49060, USA