Parent–offspring recognition in Brandtʹs voles, Lasiopodomys brandti

We investigated social interaction behaviour (amicable versus agonistic) to evaluate parent–offspring recognition in male and female Brandtʹs voles. We first examined whether the parents were able to distinguish their own familiar related offspring at the age of weaning from unfamiliar unrelated offspring. Both male and female parents, when encountering unfamiliar unrelated juveniles in a neutral arena, showed significantly more agonistic behaviour than when encountering their own familiar offspring, which suggested that adult Brandtʹs voles might be able to discriminate their own familiar descendants from unfamiliar unrelated ones. Second, we used cross-fostering to investigate the underlying parent–offspring recognition mechanism. Both males and females showed more amicable behaviour and less agonistic behaviour to familiar related offspring than to unfamiliar related offspring. Males showed significantly more amicable behaviour to familiar related offspring than to unfamiliar related offspring, and significantly less agonistic behaviour to familiar unrelated offspring than to unfamiliar unrelated offspring. Remarkably, females showed less agonistic behaviour to familiar related offspring than to unfamiliar related offspring. Furthermore, males and females did not show a significant difference in amicable or agonistic behaviour between familiar related and familiar unrelated offspring or between unfamiliar related and unfamiliar unrelated offspring. Our results suggest that the mechanism of parent–offspring discrimination in Brandtʹs voles could be familiarity.