News Briefing:

PHOENIX (Reuters) - An extremely rare jaguar has been captured and fitted with a satellite tracking collar by researchers in Arizona, who hope to shed light on the habits of one of the United States' most elusive predators.

Jaguars roam over a vast area ranging from northern Argentina in the south to the rugged borderland wildernesses of Arizona and New Mexico, where they were thought to have vanished until two confirmed sightings in 1996.

Only a handful have ever been sighted in the United States since then, and very little is known about their habits.

The jaguars, the only roaring cats in the Americas, are thought to breed in Mexico and roam up over the border.

In recent years, concern over the well-being of the U.S. population has intensified as a program to build 670 miles of fencing gathers speed along the nearly 2,000-mile (3,200-km) southwest border with Mexico.