In the latest issue of the Journal of Mammalogy, a resolution by the American Society of Mammalogists was published (resulting from the 87th annual conference held in June 2007) calling upon the U.S. Fish and Wildlife Service to get off its butt and do something about jaguar (Panthera onca) conservation in the United States. When I think of jaguar habitat the forests of South and Central America first come to mind, but jaguars have historically been found in the southwestern U.S., and even though the indigenous population was wiped out in the last century new individuals keep coming in from northern Mexico. What is strange, though, is that jaguars were listed as an endangered species in the Endangered Species Conservation Act of 1969 but not protected under the Endangered Species Act between 1973 and 1997, and there still is no plan for the conservation of these big cats in the United States. Indeed, protecting a species and allowing it to recover requires the identification of corridors and critical habitat, not just a ban on hunting a species, but so far U.S. Fish and Wildlife hasn't done very much of anything to preserve jaguars that are moving out of Mexico and into the southwestern states.
American Society of Mammalogists (2007) "Conservation of Jaguars in North America." Journal of Mammalogy Vol. 88 (6), pp.1570-1576
In Texas, where I live, jaguars are reported to have ranged as far as the northeastern border of the state, at the Red River, as recently as the late 19th century. Most recent records are from the Rio Grande Valley. I haven't heard reports of any there for years. There's hardly any habitat left down there for them to live in.