Mammalian Social Odors: A Critical Review

Publisher Summary This chapter discusses the information contained in the odorous secretions of mammals and provides a classification system based on the behavioral and chemical analyses. This classification divides social odors into two groups: identifier and emotive. Identifier odors are defined as those produced through the regular metabolic processes of the animal, without specific stimulation. The emotive odors are those produced as the result of some transient emotional state or external stimulus. The chapter categorizes nine different types of information contained in mammalian social odors: species, age, sex, colony membership, individuality, social status, reproductive state, maternal state, and stress odors. Social odors are modified by diet and hormone levels and by bacterial action. When the chemicals and bacteria responsible for producing the social odors have been identified, the responses of test animals show large individual differences. Responses to olfactory stimuli depend on hormonal and experiential factors. Theoretical models in the study of population regulation, sexual selection, kinship recognition, altruism, parental care, and territoriality infer that animals recognize particular individuals and specific relationships, and such recognition may depend to some extent on the information contained in olfactory signals.