Kin and Individual Recognition

Abstract

We summarize a series of experiments on the mechanisms of individual and kin recognition by odor cues in two species of hamsters, golden hamsters (Mesocricetus auratus) and Turkish hamsters (M brandti). Using habituation-discrimination methods, we demonstrated that the flank gland odors of full-siblings are sufficiently similar that they are not discriminated unless the subjects have interacted with the siblings that provide the stimulus odors. These experiments provide evidence for family or kinship odors, and indicate the importance of social experience for learning the cues of closely-related individuals. The individual odors of nest mates are remembered for at least 9 months after separation at weaning, providing evidence for long-term memory of individual nest mates. Other experiments indicate that hamsters recognize kin by odors, as shown by higher levels of scent marking behaviors to odors of non-kin than to those of kin. Cross-fostering studies showed that kin recognition as assessed by scent marking was based on a phenotypematching mechanism and was not based on learning the odors of nest mates. Thus, there appear to be two separable mechanisms involved in learning about odor-based recognition: (1) learning the individually distinctive odors of nest mates, and (2) developing a family-odor template for kin recognition.