Endangered animals are those species that are in danger of going extinct. Their reproductive rates are lower than their mortality rates over long periods of time, so their numbers are diminishing. The reasons for this are varied, but lately, very often involve a loss of habitat as people encroach on their living areas. When a species is listed as endangered or threatened, it is not a death sentence. Many animals, like the bald eagle and the American alligator, were on the brink of extinction and are now recovering. Many species, however, will not recover, and could be lost forever. Throughout time, animal species have been going extinct (long before people evolved); paleontologists estimate that well over 90 percent of all plant and animal species that ever existed have gone extinct.

The Koala is a small marsupial that lives in eucalyptus trees in Australia. These nocturnal (most active at night) animals spend 18 to 20 hours each day resting and sleeping. They are social animals.

Koalas are not bears; their closest relative is the wombat. The genus and species of the koala is Phascolarctos cinereus.

These herbivores (plant-eaters) eat eucalyptus leaves. Koalas have a keen sense of smell which they use to make sure the gum leaves are edible and not poisonous. They store food in cheek pouches.

Human exploitation is the primary reason penguins are endangered.
The decline of the Humboldt penguin began in the mid-19th century when the intensive activity of guano collectors disturbed and damaged nesting areas. Guano, the excrement of animals such as birds and bats, is much sought after for fertilizer.
Penguins were heavily hunted for their meat, oil, and skins. Adult penguins and chicks were captured for zoos and private collectors. People also collected penguin eggs. Sailors on the southern seas regarded penguins as a welcome, easy meal.
Penguin eggs were so prized in the Falkland Islands that the country declared National Penguin Day, a holiday when even school children were given the day off to collect eggs.
More recently, penguins have been drowning in fishing nets and on long line fishing gear. Commercial fishing also has reduced prey availability. In addition, penguins are threatened by oil spills from ships and tankers rounding the treacherous waters of the Cape of Good Hope at the tip of Africa and Cape Horn at the tip of South America.