Many bird species have males who are brightly colored and sing loudly (they're the drag queens of the animal kingdom) in order to attract a female. As females over time chose mates who were more brightly colored and who had better songs, that is why the males evolved to be that way, while the females tend to remain in more drab colors. Not all bird species are like that, though. Not being an ornithologist I really can't give you more detail than that.
But as someone who accepts evolution as true and has seen a great deal about it, yes I have examined evolution and the evidence that's been gathered for it. I've also seen the arguments for the opposite side, creationism, which has zero evidence to back up any of its claims and every argument boils down to, "the bible says it's so". The theory of evolution has been more well studied and is better supported by evidence than the theory of gravity, and gravity is something we constantly experience.