The tail of a male peacock is actually not very good for their survival: it makes them more visible to predators and makes other actions harder. If the females no longer prefer such tails, other peacocks will have a better chance of mating with the females, because they generally have better chances for survival. Therefore, the trait would gradually dissappear, and other traits (preferred by females or contributing to survival) would appear instead.
An example of natural selection is the tail of a male peacock. The females of the species choose mates based on the colors of the males’ tail feathers. If females begin using different criteria than feather color when they choose mates, what would most likely happen to the tails of peacocks over time?