What is the smallest bird egg in the world?

The smallest bird egg in the world is laid by the bee hummingbird (Mellisuga helenae), native to Cuba. These eggs measure about 1 centimetre (0.39 inches) in length and weigh less than 1 gram. Despite their tiny size, they incubate for around 14–23 days, depending on environmental conditions. Bee hummingbirds are also the smallest bird species, known for their iridescent feathers and rapid wing beats. Their eggs and nests are delicate and perfectly suited to their miniature size.