Chapter 6 - Pheromones and Reproduction in Reptiles

Abstract

Publisher Summary Pheromones are classically defined as chemicals or semiochemicals produced by one individual that effect a change in the physiology and/or behavior of conspecifics. These are chemicals involved in intraspecific communication in many animals. Reptiles rely more on their chemical senses than any other vertebrate class and many behavioral studies suggest that chemical cues are important in the communication and reproduction of many reptiles. Some recent studies, mainly with snakes and lizards, have started to reveal the importance of specific pheromones in reproduction and sexual selection. This chapter reviews the results of experiments showing that pheromones are involved in sex and individual recognition, territoriality, intrasexual aggression between males, mate choice, and reproductive decisions. Pheromones not only inform on the presence and sex of a conspecific, but may also provide reliable information on the characteristics, quality, and health state of the sender, which other individuals may use in their reproductive decisions. The chapter also helps understand how chemical communication systems evolved in reptiles by examining both the diversity of pheromones and the underlying physiological and endocrinological mechanisms involved in their production and expression. These physiological mechanisms, specially the alternative roles of some chemicals in other metabolic functions such as the maintenance of the immune system, may also explain how pheromones have evolved to be used as reliable sexual signals in reproduction.