Signaling pheromones I discrimination and recognition

My dear friend, the last time you were so good as to come and see me - for nobody comes any more to see the wretched invalid I am -1 was obliged to take the chair you sat in and keep it out in the courtyard for three days it was impregnated with scent. 

Optimus odor in corpore est nullus [The best body odor is none]. 

Signaling pheromones are animal-produced, interindividual chemicals that modulate behavior in conspecifics. Like visual and auditory signals, they have comparatively rapid effects exchange of signals takes seconds or minutes. (Priming pheromones [Ch. 8], hy comparison, trigger slower endocrine or developmental processes.) The pheromone concept, originally based on insects (Karlson and Luscher, 1959), has been debated for vertebrates, notably mammals (e.g. Beauchamp etal., 1976 Johnston, 2001). Often it is better to use the term body odors to avoid particular assumptions. Now the term pheromones is widely used for vertebrates, without any particularly narrow definition implied. 

A pheromone is functionally defined as a conspecific compound(s) that affects a receiver. Sources such as urine or gland secretions typically contain many compounds of which only some are pheromonally active. So in most cases, a pheromone is more than a single compound and less than a secretion ( scent ), it is rather a group of active compounds in a secretion or excretion that supply information to, or change behavior in, another conspecific. 

The following text discusses first the ability of animals to distinguish and recognize other animals by odors without necessarily exhibiting specific behaviors and then the behaviors that are modulated by status signals. Chapter 7 discusses the sexual and evolutionary implications of signaling pheromones. 

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The multifaceted function of cuticular hydrocarbons necessitates further theoretical as well as empirical clarification. For example, their use as both fertility signals and nest-mate recognition pheromones may seem contradictory, since the first function requires within-nest idiosyncrasy, i.e., for discriminating fertile from sterile individuals, while the second function requires within-colony odor uniformity. The response threshold hypothesis (Le Conte and Hefetz, 2008) attempts to resolve this apparent conflict in function, as well as to provide a suitable framework for future experiments to test specific parts of the hypothesis. 

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