Kinglet bird

   The kinglet is any of several small songbirds. It is greenish with a gray breast and brightly-colored crown. The two North American species are the golden-crowned and the ruby-crowned. They live far north, but some are so sturdy they do not migrate to a warmer climate in winter.
   Kinglets are among the smallest of all passerines, ranging in size from 3.2–4.3 in (8–11 cm) and weighing 0.2–0.3 oz (6–8 g).
   The kinglet's scientific name Regulidae is derived from the Latin word regulus for "petty king" or prince.