But a new generation of highly toxic, long-lasting poisons is killing not only rats, mice and ground squirrels, but whatever feeds on them, too. As a result, toxins are rippling outward from warehouses to woodlands, from golf courses and housing complexes to marshes and nature sanctuaries. In California, the victims include bobcats, barn owls, red-tailed hawks, coyotes, kit foxes, kestrels and scores of other predators and scavengers.