(MODEL RELEASED IMAGE). Emil Madsen stops to look for prey (seals, polar bears, musk ox, and geese) while the dogs take the moment to rest. Here he is looking for seals near the ice edge (a giant iceberg is in the open water in the background) The family has been traveling by dogsled for a good portion of the day. When the snow crust is hard enough to ensure that the dogs won't break through, they can pull the half-ton weight of the sled for hours on end. On level ground, the animals pull at about the pace of a running human, but the sleds can whip down hills so fast that drivers must step on the brake at the rear of the sled to avoid running over their dogs. (Supporting image from the project Hungry Planet: What the World Eats.)