540/5000 This is one of the smallest hummingbirds - and one of the smallest birds in the world! The smallest in the bird world, the Cuban bee hummingbird (Mellisuga helenae) , is only 4 mm shorter on average. The male (6.5 cm) in the picture is slightly larger than the female (6 cm) and weighs only around two grams (0,1 oz)! They are amazingly similar to a bee, both in the way they fly and when they land on a flower to sip nectar. The sound of the wings resembles that of a large insect, but otherwise this bird is mostly quiet. This male has half of its bill covered with nectar after a visit to a flower.