The blue-naped mousebird (Urocolius macrourus) is a rather little bird, only reaching a length of about 13 to 14 inches. The long tail and turquoise blue patch on the nape of the neck are this bird’s defining features. Birds that are adults often have gray-white to ash brown plumage, a long tail, a crest on top of the head, a black-red bill, and a blue nape.