Smallest organisms
With a mass of approximately and a length of 5 centimetres (2.0 in), the bee hummingbird ("Mellisuga helenae") is the world's smallest bird species and the smallest warm-blooded vertebrate. Called the "zunzún" in its native habitat on Cuba, it is lighter than a Canadian or U.S. penny. It is said that it is "more apt to be mistaken for a bee than a bird". The bee hummingbird eats half its total body mass and drinks eight times its total body mass each day. Its nest is 3 cm across.
Cardinal (bird)
They are robust, seed-eating birds with strong bills. The family's smallest member is the 12-cm (4.7-in), 11.5-g (0.40-oz) orange-breasted bunting. They are typically associated with open woodland. The sexes usually have distinctive appearances. The northern cardinal type species was named by colonists for the male's red crest, reminiscent of a Catholic cardinal's biretta.