There are more than 9,800 known species of birds. The smallest is the male bee hummingbird (Mellisuga helenae) found in Cuba., which is 2.25 inches (5.7 centimeters) long and weighs only 0.056 ounces (1.6 grams). The bill and tail account for half of this length. Its body is the size of a large bumblebee!
The largest bird is the ostrich Struthio camelus, which can weigh up to 340 pounds (154 kilograms). - The largest and strongest living bird is the North African ostrich (Struthio camelus . Males can be up to 9 feet tall and weigh 345 pounds, and when fully grown the have one of the most advanced immune systems of any animal.