Definition: Sexual dimorphism is a phenotypic difference between males and females of the same species. The prototypical example is for differences in characteristics of reproductive organs. Other possible examples are for secondary sex characteristics, body size and morphology, ornamentation and behavior.
Definition: Description of the relationships among individuals within a population of organisms, including reproductive relationships (mating system), relationships within each sex, adult – young interactions, helpers and cooperation (group living).
Definition: position of an organism in a food web. May be described verbally with descriptors including primary producer, herbivore or carnivore. If described numerically, 1 indicates a primary producer, 2 a herbivore, and so on up the food web.