There are over 13,000 known species of mammals and birds, as well as thousands of reptiles, amphibians and fish, millions of invertebrates and some 250,000 flowering plants.
Extinction is a natural feature of the evolution of life on Earth.
But in recent times humans have been responsible for the loss of most of the animals and plants that have disappeared. Many species are declining in number because of loss of habitat and increased exploitation as human populations grow. Trade has now also become a major factor in the decline as improvement in transport facilities has made it possible to ship live animals and plants and their products anywhere in the world. The wildlife trade is a highly lucrative business and involves a wide variety of species, both as live specimens and as products. Millions of animals and plants are traded each year to supply the demand for pets and ornamental plants.