Leopard seals are some of the Antarctic's top predators. They are skilled hunters that hide under overhanging ice to surprise their favorite foodpenguins. Penguins make up about 87 percent of the leopard seal diet.
One seal in this picture (bottom) is wearing a National Geographic Crittercam. Crittercams include video cameras and other information-gathering devices. They can be attached to animals without hurting them. Crittercams help scientists study the animals that wear them.