Gray seal pup triples its weight since birth

A gray seal pup, born just two weeks ago, has tripled in size since its birth.

The male pup at Brookfield Zoo in Illinois weight just 36 pounds when he was born the day after Christmas. Now, he’s already more than 100 pounds, and it’s all due to fat-rich milk from his mother, zoo officials say.

It’s not unusual. Gray seal pups tend to put on several pounds every day. Experts say they need to grow quickly because once they are weaned and grow their darker coat, pups are on their own to hunt. 

There are 25 gray seals at 10 accredited zoos in North America, five of which are at the Brookfield Zoo.