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.
Lesser frigatebird
The lesser frigatebird is the smallest species of frigatebird and measures in length with a wingspan of and long forked tails. Male birds weight . Female birds are heavier and weight . Like all frigatebirds the male has a large red sac on the front of the throat which is inflated during courtship. Courtship display also involves a variety of calls, bill rattling and spreading of the wings. The male is mostly all black save for a white patch on the flank which extends on to the underwing as a spur. Males also have a pale bar on the upper wing. Females have a black head and neck with a white collar and breast as well as a spur extending on to the underwing. The female also has a narrow red ring around the eye. Juveniles and immature birds are more difficult to differentiate but the presence of the spurs of white in the armpits is a helpful distinguishing sign.