Meeting Abstract
The ability to differentiate between kin and non-kin may confer fitness benefits such as altruism or inbreeding avoidance. In parental care-giving species, parents may also benefit from the ability to discriminate offspring between unrelated infants or juveniles to ensure that the appropriate animals are receiving care. Sex differences in offspring discrimination ability may arise if parental behaviors and their underlying mechanisms differ between males and females of a given species. For example, unique to mammals, mothers must gestate and produce milk while fathers do not. Consequently, mammalian mothers experience different hormone changes than fathers, even if the two parents provide otherwise equal care. Thus, we hypothesized that mammalian mothers and fathers may differ in offspring discrimination. We tested this hypothesis in the monogamous, bi-parental California mouse (Peromyscus californicus). At four different time points during the postpartum period (PPD 3, 7, 16, and 28), each parent was housed individually and allowed to interact with two mesh balls, one containing one of its own pups and the other containing an unrelated, age-matched pup, for 10 minutes. We compared behavioral responses to the pups, including the duration of time that each animal spent in proximity to each ball, the number of bouts and latency to approach each ball, and the first and second ball approached, between mothers and fathers, finding no significant difference between the sexes. We further examined possible longitudinal changes in offspring discrimination within individual parents, again finding no significant changes over time. Therefore, we found no evidence for sex-differences in offspring discrimination in the California mouse.
