Sexual dimorphism .January 13, 2021
Sexual dimorphism is the condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs.The condition occurs in many animals and some plants. Differences may include secondary sex characteristics, size, weight, colour, markings, and may also include behavioral and cognitive differences. These differences may be subtle or exaggerated, and may be subjected to sexual selection and natural selection. The opposite of dimorphism is monomorphism.
The peacock, on the right, is courting the peahen, on the left.Male (bottom) and female mallards. The male mallard has an unmistakable bottle green head when its breeding plumage is present.Orgyia antiqua male (left) and female (right).
Ornamentation and coloration :
Common and easily identified types of dimorphism consist of ornamentation and coloration, though not always apparent. A difference in coloration of sexes within a given species is called sexual dichromatism, which is commonly seen in many species of birds and reptiles. Sexual selection leads to the exaggerated dimorphic traits that are used predominantly in competition over mates.