The Guardian The Porcupine herd on its home range - the Alaskan National Wildlife Refuge. It's feared the decision last year by the U.S. Senate to allow oil drilling there will disrupt and endanger the herd, considered the largest and healthiest on the continent. Photo by U.S. Fish & Wildlife Service. Oil extraction in Alaskan wilderness area would be an ‘irresponsible business decision’, trillion-dollar investors say. More here. RELATED: "Oil drilling threatens yet another caribou herd" - by Larry Powell.