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.
Little bronze cuckoo
The little bronze cuckoo ("Chrysococcyx minutillus") is a species of cuckoo in the family Cuculidae. It is found in Southeast Asia, New Guinea and northern and eastern Australia. Its natural habitat is subtropical or tropical moist lowland forests. This is the world's smallest cuckoo, at 17 grams and . The subspecies "rufomerus" and "crassirostris" are sometimes given specific status.