Each spring, starting in late February or early March, female harp seals move out onto the sea ice, each one giving birth to a single, snowy-white pup. The pupping grounds of the “Gulf Herd” are near the Magdalen Islands (the “Front Herd” are found off Labrador), and here there can be up to 2,000 female seals per square kilometer. Their pups are known as “whitecoats,” and they are fed a rich milk containing 45 percent fat (compared to 4 percent in cow’s milk). They put on weight rapidly and are weaned in as little as 12 days, and then abandoned by their mothers. Why the nursing time is so short is not clear, although it is an effective way to get the youngsters ready to swim before the ice breaks up in mid-March. This way, they spend the minimum time on the ice, where they are vulnerable to polar bears on the lookout for food. The seals are also the target of a controversial cull. A Seal Interpretive Center on the Magdalen Islands explains the environmental and social aspects of seals in the area, and helicopter tours take visitors onto the ice for close encounters with baby seals.