The size of a ruby-throated hummingbird is typically between 2.8 and 3.5 inches in length and weighs between 2.5 and 4 grams. It is the smallest bird in North America and one of the smallest bird species in the world.
The ruby-throated hummingbird’s small size gives it a number of advantages. Its small size allows it to fly quickly and maneuver easily, which is essential for finding food and avoiding predators. Its small size also allows it to conserve energy, which is important for a bird that has a very high metabolism.