What is a bird?
Birds are unique as the only animal's which have feathers covering their body. Feathers are made of keratin which is the same substance that human hair and nails are made from.
The feathers serve many functions in birds, but the most obvious role is to enable birds to fly. Feathers also help to protect the birds from the elements. Feathers are able to provide birds with insulation and waterproofing as well as helping to block the UV rays from reaching the birds skin.
Not all birds are able to fly and not all animals that are capable of flight are birds. For example bats, which are mammals are able to fly, and insects which are arthropods were flying around several millions years before birds took to the sky. Some of their bones are hollow to allow them to fly.
All birds lay eggs that have hard, waterproof shells that they create nests for. Birds incubate their eggs until they are ready to hatch. The parents continue to care for the young and bring food to the nest sites for the chicks.
More on Birds
Birds do not have teeth. Instead they have bills that are made from keratin the same substance that hair and fingernails are made from. The bills come in a wide variety of shapes and sizes and are adapted to be suitable for the diet of the species.
Some species of birds have chicks that are already covered in down like chickens that are able to start finding their own food – they are called precocial. Other chicks like robins hatch with no feathers and they are helpless and depend on their parents to feed them. They are called altricial.
Record Breaking Birds
The world's smallest bird
The smallest bird is the male bee hummingbird which is 5.7cms (2.25in) long and weighs only 1.6 grams (0.056 oz).
These tiny birds are powered by nectar which they spend up to 15% of their day searching for.
While in flight their wings which have a span of just 5.2-6.6cm (1.3-1.5in) across will beat up to 80 times per second. This increases to 200 times when mating. Learn more about them with our fact file below.
The world's Largest bird
The largest bird of all is the ostrich. Ostriches are not able to fly and they have a large body, small head, long legs and a long neck.
Even though they can’t fly they are great runners who can run at speeds of up to 72 km/h (45 mph) for about half an hour.
Adult ostriches weigh between 100 kg to 160kg (220 to 350 pounds) and measure between 237 cm and 282 cm (7 to 9 ¼ feet).
Examples Of Birds
Below are some examples of the groups of birds which exist. How many do you know?
An American Museum of Natural History Study suggests there may be as many as 18,000 species of bird on Earth.
Bird Fact Files