What is the passage mainly about?

Many kinds of animals are endangered by human beings. The United States government list of endangered species includes tigers, grizzly bears, some kinds of whales, and over three dozen species of butterflies. What has led to the scarcity of these animals, which may become extinct without vital protection?
     One important factor is that many animals have been widely hunted and killed for food, or for their beautiful skins. Besides, some predators are threatened by ranchers to protect their sheep and chicken, such as eagles or wolves. Moreover, some species, like polar bears, are endangered because humans are successfully competing with them for the use of environmental space.
     With various animals being killed for food, for decoration, and for the protection of domesticated animals, or dying because of unfortunate contact with human environments, it is not surprising that some are becoming scarce, that the number of species on the endangered list is growing every year. Furthermore, it is important to understand that individual species are not the only factors involved in fids dilemma. Endangerment is a broad issue, one that involves the habitats and environments where species live and interact with one another. Man is discovering that his world includes the other animals in it, and one can only hope this discovery is not coming too slowly or too late.