Male jaguars are reportedly crossing into the Southwestern United States from Mexico, often using the same routes as drug smugglers.

Although nobody knows exactly how many jaguars have wandered into southeastern Arizona and southwestern New Mexico from their Mexican breeding grounds, several organizations are working to protect the threatened species, The New York Times reported.

Conservationists, upset over the killing of the animals by Mexican bounty hunters, want U.S. federal officials to declare parts of Arizona and New Mexico critical habitat for jaguars. But opponents say that's unnecessary since the animals show no signs of breeding in the United States.

Jaguars once roamed much of the Southwestern United States, as well as Central and South America, but they were trapped and hunted to near extinction as U.S. ranchers took cattle into the region, the newspaper said. The last known resident U.S. female jaguar was killed in 1963 near the Grand Canyon.

Conservationists are worried about a planned 700-mile-long fence along the U.S.-Mexican border. Jon Schwedler of the Northern Jaguar Project told the Times, if such a barrier is built, "it'd be all over ... you could kiss the jaguar goodbye."

Copyright 2006 by United Press International