Blog: Center for the Science of Animal Care and Welfare

Gray Seal Born at Brookfield Zoo


One of the last births that took place in 2017 at Brookfield Zoo was a gray seal, born on December 26. The pup is currently behind the scenes nursing, learning how to swim, and bonding with his mother, 13-year-old Lily. This pup is the third for Lily and the sire, 13-year-old Boone.

At birth, gray seal pups are born with long, white fur called lanugo (pronounced la-NOO-go), which is molted in two to four weeks and replaced with shorter, stiffer hair similar to that of adults. Guests will most likely not be able to see the pup at the outdoor habitat at Pinniped Point prior to the pup molting.

The male pup weighed 36 pounds at birth, and he is on track to quadruple his weight by the time he is weaned at 3 weeks of age. The fat-rich milk he receives from his mother, allows the pup to put on a lot of weight in a short amount of time. Gray seals have one of the shortest nursing periods of pinnipeds (group of marine mammals that are winged- or web-footed). In the wild, pups are born in the winter and put on several pounds a day. The blubber is a great insulator. They also need to grow quickly because once they are weaned and grow their darker coat, pups are on their own. They need to be able to fend for themselves and go out to sea to learn to hunt.

gray seal pup born at Brookfield Zoo

The pup’s birth is very important to the gray seal population in North American institutions accredited by the Association of Zoos and Aquariums. Although their numbers are not threatened in the wild (they are found in the Western North Atlantic, the Eastern North Atlantic, and the Baltic Sea), currently there are only 25 individuals in 10 institutions. Brookfield Zoo is home to five individuals. Rita Stacey, curator of marine mammals for the Chicago Zoological Society, which manages Brookfield Zoo, is the Association of Zoos and Aquariums’ studbook keeper and population management planner for gray seals. In this role, she documents the pedigree and entire demographic history of each individual in the gray seal population. These collective histories are known as the population's genetic and demographic identity and are invaluable tools used to track and manage each animal, as well as to make breeding recommendations for the sustainability of the population.

Posted: 1/9/2018 12:17:17 PM by Steve Pine

Center for the Science of Animal Care and Welfare

Read the latest exciting stories about how our experts are advancing the science of “animal-directed” care through innovative programs at Brookfield Zoo and global field efforts.


Subscribe to our Blogs!RSS