The human population is growing at a tremendous lick, bulging to almost 6.4 billion people worldwide, according to current U.S. census estimates. The U.S. population grows about 1 percent a year, and could top 300 million within four years. This spells bad news for the nation's animal populations, as sprawling urban centers, industrial infrastructure, and food and energy needs threaten to destroy many creatures' natural habitats.

Here, we take a look at ten threatened and endangered species—from mighty hunters to smelly rodents to a four-inch-long minnow found only in New Mexico—for whom the survival clock is already ticking. All is not lost, but without some urgent action some of these precious beasts won't be with us in generations to come.