Which is the smallest bird?
With a mass of approximately 1.6–2 g (0.056–0.071 oz) and a length of 5–6 cm (2.0–2.4 in), it is the smallest living bird. The male has the green pileum and fiery red throat, iridescent gorget with elongated lateral plumes, bluish upper-parts, and the rest of the underparts mostly greyish white. The male is smaller than the female. The female is green above, whitish below with white tips to the outer tail feathers. Compared to other small hummingbirds, which often have a slender appearance, the Bee Hummingbird looks rounded and chunky.
As the smallest bird in the world, it is no larger than a big insect and, as its name suggests, is scarcely larger than a bee. Like all hummingbirds, it is a swift, strong flier. It also can hover over one spot like a helicopter. The wingbeat frequency of the bee hummingbird has not been measured, but in flight its wings beat so fast that they look like a blur to human eyes.