The feathers of hummingbirds are generally blue or green, and the lower body is lighter. Some males have crowns or slender tail feathers. Most of the male birds are blue-green, and some are purple, red or yellow. The female's body feathers are dim. The northernmost species is Selasphorus Rufus, which breeds from Southeast Alaska to northern California. Hummingbirds are all small birds, some are tiny.
Hummingbirds are all small birds, some are tiny. Patagona gigas, the largest hummingbird in western South America, is only 20 centimeters (8 inches) long and weighs about 20 grams (0.67 ounces). The smallest hummingbird (melisuga helenae or Calypte helenae) is found in Cuba and Pine Island. It is slightly longer than 5.5cm (2.12in) and weighs about 2G. This is the smallest living bird, the smallest warm blooded vertebrate with the little shrew.
Hummingbirds like flowering plants (especially red flowers), including shrimp flowers, upside down Golden Bell (also known as hanging bell flowers), fishing bell willows and so on. Hummingbirds feed on the nectar of these plants. They are also important pollinators, especially for long tube flowers. Most hummingbirds also feed on insects.