Field Guides

An endangered species is one that is in danger of becoming extinct in all or most of the places it is found. (Extinct means every member of that species is dead.) These are usually species that have become very rare because they’ve been hunted or collected, had their habitats destroyed, been affected by diseases, or been affected by introduced species.

Habitat destruction may be the most common reason that species become endangered. Habitat destruction includes things like polluting waterways, cutting down forests, changing the qualities of rivers through dam building, plowing grasslands for agriculture, and many others. It also includes the effects of global climate change in some places (such as warmer sea temperatures killing coral reefs),

Some species became endangered because they were hunted, collected (plants and animals that don’t move around), or persecuted (killed, but not to eat or otherwise use). For example, timber wolves and mountain lions were once killed in large numbers because people were afraid of them or thought they were a threat to humans and their animals.

In recent years, more species are becoming endangered because of the effects of introduced species and the spread of diseases. For example, malaria has played a big role in the decline (and extinction) of many native Hawai’ian birds. Malaria is an introduced disease that is spread by introduced mosquitoes. (Introduced means it didn’t use to occur in Hawai’i.)

Because endangered animals are sometimes brought into zoos or other places for captive breeding and protection, an animal can also be in danger of becoming “extinct in the wild,” meaning that there are none of these animals left in the wild. The hope for animals like these is that they can be bred in captivity and later released back into the wild when their wild habitats have been protected.