This document provides information about endangered and threatened species. It notes that species are becoming extinct at an alarming rate, with estimates that one fifth of all species will vanish by the end of the century. An endangered species is on the verge of extinction unless rescue steps are taken, while a threatened species is likely to become endangered without habitat and pollution protections. Habitat destruction, overexploitation, invasive species, disease, pollution and limited distributions are reasons for endangerment. Examples of well-known endangered animals include African elephants, bald eagles, black rhinos, blue whales, giant pandas, gorillas and manatees.