Newborn seals have yellow fur because of amniotic fluid and are still wet. When the pup dries, it is called a yellowcoat. The amniotic stain fades and the fur turns white within a few days and it gets the name whitecoat. Nursing their young lasts for about 12 days. Cows frequently return to their pups to suckle. While she is suckling, the mother does not eat—rather, she draws on her reserves of fatty blubber to produce the milk. Pups grow rapidly, at the end of nursing, most pups weigh 80 lbs or more. The mothers then leave their fully fed pups and join the bulls to mate. At this age of about 12 days, pups first become “greycoats” as grey juvenile coloring grows under their white fur then “ragged-jackets” when white fur begins to fall out in patches. The United States banned the hunting and import of whitecoats in 1972, through the Marine Mammal Protection Act.