Their family includes the smallest known bird in the world, but even the largest species, which are 10 times larger than the tiniest, don't weigh a whole ounce. A hummingbird's light weight allows him to fly easier since he doesn't need to build up a lot of momentum to get his body off the ground.
Moe than 300 types of hummingbirds exist. All are lightweights. The average hummer weighs around 4 grams, or 0.141 ounce. Hummingbirds can weigh as little as 2.4 grams and as much as 4.5. As a simple comparison, a U.S. penny weighs 2.5 grams and a U.S. nickel weighs 5 grams. Nearly one-third of a hummingbirds weight, or an average of 30 percent, is muscle. A hummingbird's egg weighs 0.4 grams to 1.4 grams; a newly hatched bird is about 1 inch long and 0.62 gram.
When it's time to migrate, hummingbirds pack on the the grams. Prior to migration they feed heavily and bulk up, sometimes doubling their weight. A 4-gram hummingbird could be a portly 8 grams at the beginning of the long trip.
Males and Females
Female hummingbirds are usually slightly larger and weigh a little bit more than their male counterparts. The average male ruby-throat hummingbird weighs between 2.4 grams and 3.6 grams, while the female ruby-throat tips the scale at 2.8 grams to 4.5 grams. Similarly, the average male Rufous hummingbird is 3.2 grams, compared to the female's average 3.4 grams. Females are generally larger because of their reproductive roles of producing eggs, keeping hatchlings warm and sharing food with their young.
A hummingbird uses a tremendous amount of energy as it flaps its wings up to 75 times every second during normal flight. To keep its weight up it must consume a tremendous amount of food. A hummingbird eats up to one-half of its total body weight in nectar every day. This is the equivalent of a human eating 155,000 calories.
The Bee hummingbird is the smallest type of hummer, weighing in at an average of 2 grams, or less than a penny. This little bird measures a total of 2 inches from the tip of its bill to the end of its tail. The largest hummer, the Giant hummingbird, is so large that it is often mistaken for a swallow. This giant of the species weighs a whopping 20 grams, or the equivalent of a stack of four nickels.