Mule deer range is characterized by beautiful but unforgiving landscapes. Mule deer numbers have always been determined in the margins between ever-changing weather patterns, food sources and predator numbers. Today they face additional problems like loss of winter range, obstacles to migration, poaching and invasive plants. Because their survival is so dependent on these razor thin margins, scientific research has driven conservation of the species. Idaho Department of Fish and Game biologist Mark Hurley has been studying mule deer for much of his twenty plus year career. He's scrutinized everything from loss of nutrition to predator reduction in his quest to better understand mule deer survival and what management actions can be done to improve that.