What is the smallest species of bird?

The smallest species of bird is the bee hummingbird (Mellisuga Helena), native to Cuba and the Isla de la Juventud. This tiny bird measures just 2.2 inches (5.5 cm) in length and weighs about 1.98 grams (0.07 ounces). Despite its small size, the bee hummingbird is incredibly agile, capable of hovering in place while feeding on nectar. It has a rapid metabolism and must feed constantly to maintain its energy levels, often visiting hundreds of flowers each day.