The study of birds is called ornithology; it is a hobby that many people love pursuing. Many bird lovers love bird watching to study birds. Bird lovers often care so much for their birds that they have birdbaths and birdfeeders, along with their regular birdcages and birdhouses. For those who are interested in pursuing this hobby, there are many bird books available through which one can obtain interesting information about birds. And for friends who love birds, you can always present them with one of the many bird lover gifts that are available at the bird shops!

Birds are mainly found on major land masses from the poles to the tropics and over the seas and oceans. The most common wild bird in the world is the Red-billed Quelea from Africa, while the most common domestic bird is the Red Junglefow, commonly known as the common domestic chicken. The rarest bird is hard to distinguish, as a large number of birds have been considered rare for quite some time like the Sudanese Red Sea Cliff Swallow. Since the 1600s, human interference alone has led to the extinction of about 115 species of birds. The largest living bird is the Ostrich, which is 2.74m high and weighs at the most 160 kilograms, while the heaviest flying bird is said to be the Kori Bustard of Africa, weighing up to a record 19kg! Its hard to believe, but the smallest bird is the Bee Hummingbird from Cuba, which weighs only 1.6 grams!

The world of birds is indeed a vast one with about 9,703 species of birds divided into 23 orders, 142 families and 2,057 genera. This is just the number of types of birds found. If we look at the total number of birds there may be on the planet, scientists suggest there may be between 100,000 to 200,000 million adult birds on the planet at any one time.