Why do animals become extinct?

Since the time animals have evolved species continue to become extinct. The most well-known example of extinct species is that of the dinosaurs. Often the species cannot adjust fast enough to the changing environmental conditions, or new species arise and displace the existing ones. Today, many species are becoming extinct because of the actions of humans. Elephants, big cats, and rhinos are hunted ruthlessly, forest areas are cleared, and the grey whales are endangered. These are only a few of the species mentioned in the ‘Red List’. On a positive note, new animal species are also being discovered.