Jaguars are the largest of South America's big cats. They once roamed from the southern tip of that continent north to the region surrounding the U.S.-Mexico border. Today significant numbers of jaguars are found only in remote regions of South and Central America—particularly in the Amazon basin.
Why are they endangered?
The largest threat to the jaguar is humans. Jaguars are hunted and killed for their coats, as well as killed by farmers. Farmers kill the large cats because Jaguars eat livestock. Jaguars have to resort to this because much of their habitat is being taken over by cities and new farmland. The rise of cities has also created smog, which prevents growth of tall grasses where jaguars like to hide.
How we can help prevent extinction.
The ideal thing would be to move away from and prevent further destruction of their habitat. While that can't be done, there have been laws set in place that prevents the selling of jaguar fur in the U.S. This keeps poachers from killing the jaguars because they cannot make a profit.