THE WORLD OF THE BIRDS

INTRODUCTION 
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It is thought that there are approximately 10.000 species of birds which makes them the second biggest group of invertebrates.

Birds are the only group of animals to possess feathers, they lay eggs, have bills instead of teeth, a strong four chambered heart and their skeleton is made of hollow bones.

The birds’ forelegs have evolved into wings which enable them to fly, though not all birds can fly. Their unique respiratory and digestive systems are highly adapted for flight. Some species like the parrots are among the most intelligent animals.

Birds are social animals and use song, call notes and behavior to communicate with each other. An estimated 90% of all bird species are monogamous during one or more breeding seasons, some mate for life. Eggs are usually laid in a nest and are incubated by the parents. Breeding seasons are relatively long.

Parrots are found mostly in warm and tropical regions. There are over 350 parrot species divided in two families: the Psittacidae or true parrots and the Cacatuidae or cockatoos. Most parrots are green with other bright colors, some species are multicolored. They exhibit little or no sexual dimorphism. Regarding their life span, parrots can live between 25 and 50 years but Amazons and Cockatoos may live 70 years and Macaws up to 100 years!

Do they talk? Many species of birds mimic the human voice or other sounds. A structure in their throats is thought to be the source of the sounds they make. Birds don’t properly talk; they merely mimic sounds that occur regularly in their environment. Some African Greys boast vocabularies of up to 500 words.

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