aka. Indian Peafowl or the Green Peafowl.
The difference being the color of either the blue peacock or the green peacock.
I will talk about Peacocks and sexual dimorphism. Example of Sexual Dimorphism in male birds:
The peacock uses his plumage to scare off other animals and attract a mate. The females will often judge if the male is good enough by the length and the kind of eyespots it has. Peacocks are surprisingly fast on foot and can fly if they want.
In Charles Darwin’s book, The Descent of Man and Selection in Relation to Sex, he says:
The sexual struggle is of two kinds; in the one it is between individuals of the same sex, generally the males, in order to drive away or kill their rivals, the females remaining passive; whilst in the other, the struggle is likewise between the individuals of the same sex, in order to excite or charm those of the opposite sex, generally the females, which no longer remain passive, but select the more agreeable partners.
This directly relates to Peacock, whose females will judge the male based on their appearance and performance. The condition of the male peacocks plumage is a hint to how healthy the peacock is, and in some way, an indication to the male’s ability to survive (basically if he has good and strong genes). For an example, there was a test done by a professor of Newcastle University, named Marion Petrie, who cut out the eyespots on some peacock, and witnessed that female peacocks were less interested in those males. Less eyespots means less effectiveness in scaring off predators, so lower chance of survivability, and poor genes. There have been some debate that female peacocks do not care about a male’s plumage, but there have been more substantial studies that females do care.