There are over 9500 species of Birds in the world. Scientists typically group them in to 30 categories. Birds are the most widespread of all animals around the world.

Characteristics that are unique to birds are 1) Feathers, 2) Bills, and 3) a furcula (fused collarbone, or Wishbone)
Approximately 2/3 of all the bird species are found in tropical rain forests.

Many birds consume 1/5 of their body weight in food every day to get the energy they need to Fly
To make them lightweight, most birds do not have bladders to store Urine. Rather than producing liquid urine to get rid of wastes, they produce a white, pasty substance. However, while an ostrich does not have a bladder like a mammalian bladder, it is unique among birds because it does have a complete separation of feces and urine.

Bird’s lungs are more complicated and efficient and take up more space than those of mammals, such as human’s lungs compose about 1/20 of its body, but a bird’s takes up 1/5.

The Australian pelican has the longest bill of any bird in the world. It is nearly 2 feet (0.5 m) in length. The sward- billed hummingbird, with its 3.9 inch(10 Cm0 bill, is the only bird with a bill that’s longer than its body.

The song of a European wren is made of m ore than 700 different notes a minutes can be heard 1650 feet (500m) away.

Owls cannot swivel their eyes. Instead they move their heads completely around to see straight behind them. They live on every continent except Antarctica. Soft fringes on their wings make their flight essentially silent.

The only bird with nostril at the end of its beak is the kiwi. This placement helps it sniff for food, such as worms and insects of the ground. It often snorts to clear its nostrils.