What is the smallest bird in the world?

The smallest bird in the world is the bee hummingbird (Mellisuga helenae), native to Cuba and the Isla de la Juventud. It measures about 5–6 centimetres in length and weighs just 1.6–2 grams. Despite its tiny size, the bee hummingbird is incredibly agile and can beat its wings up to 80 times per second, enabling it to hover and fly backward. The bird feeds on nectar and plays a vital role in pollination. Its feathers are iridescent, giving it a jewel-like appearance. This species is a marvel of adaptation, perfectly suited to its environment.