Nature produces some truly extravagant costumes, and birds have evolved more than their fair share of dazzling outfits. Often, it's the male birds that steal the show with bold colors and unfurling ...

Small but speedy. Tiny but aggressive. Little bodies, big appetites. Hummingbirds are a study in extremes. They are the lightest North American birds. Most weigh less than two pennies at 3 to 4 grams.