A male peacock displaying its open tail

Sexual dimorphism

Sexual dimorphism describes animals where there is a physical differences between males and females of the same species (other than in the sex organs). One may be significantly larger than the other, colouration may be different or one might have additional body parts such as antlers, ornate plumage or a mane. In the rarer cases where females are larger or more ornate it is termed reverse sexual dimorphism.

Watch video clips from past programmes (7 clips)

In order to see this content you need to have an up-to-date version of Flash installed and Javascript turned on.

View all 7 video clips

Animals with this behaviour






Crabs, shrimp and krill


Other Morphology behaviours

BBC News about Sexual dimorphism