Hummingbirds lay the smallest eggs of all birds. Their eggs measure less than 1/2 inch long but may represent as much as 10 percent of the mother’s weight at the time the eggs are laid. Hummingbirds are native species of the New World and are not found outside of the Western Hemisphere except in a few zoos or aviaries. There are no hummingbirds found in Europe, Africa, Asia, Australia or Antarctica.