Twice a year a river of raptors soars overhead between British Columbia and Argentina on their seasonal migrations. Ecologist Charles Post joins them for part of their journey south through the rugged sagebrush-covered canyons of Nevada’s Goshute and New Mexico’s Manzano mountains. Workers with Hawkwatch International have been counting, measuring, banding and marveling at Cooper’s hawks, red-tailed hawks and golden eagles for the last 30 years. The birds’ fierce eyes and powerful wingspans indicate they, as well as the animals they prey on, are doing well. But for conservation to succeed, there must be a global effort. It takes the entire Western Hemisphere to raise a hawk.