Jonathan Michaluk, age 11, of Winnipeg, Manitoba, Canada, for his question:

HOW MANY KINDS OF BIRDS ARE THERE?

About 9,000 different species of birds can be found in every section of the world.

Birds make up the class Aves, which is one of the seven classes of vertebrates. A vertebrate is an animal with a backbone. Ornithologists then divide all living birds into 27 separate orders which are based largely on their internal features.

Included in the various orders are flightless birds, which include penguins and ostriches; weak billed birds; water birds; sea birds with tubelike nostrils; water birds with webbed toes; long legged wading birds; daytime birds of prey; fowllike birds; land dwelling birds; shore birds and waterfeeders; pigeonlike birds; seed  and fruit eating birds; tree dwelling birds; nighttime birds of prey; owllike birds; strong winged birds; long tailed tropical birds; birds with large bills, and perching birds.