Smallest Bird : Bee hummingbird

The bee hummingbird or zunzuncito (Mellisuga helenae) is a species of hummingbird that is endemic to dense forests and woodland edges on the main island of Cuba and (formerly) on the Isla de la Juventud, also part of the nation of Cuba. 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