Miscalibrated Internet Receptor Stalks

Pinnipednesday - Halichoerus grypus Edition

I don't know about you, but two weeks is far too long a time to go without learning about pinnipeds. It's not right, I tell you, it's not right!

The Gray Seal (Halichoerus grypus) is the only extant member of the Halichoerus genus, and its scientific name translates to "hook-nosed sea pig." Gray Seals are true seals, which means that they are an earless seal belonging to the family Phocidae. In spite of their name, their coat varies in color from gray to brown. Males tend to have darker coats with lighter splotches, and females tend to have lighter coats with darker splotches. Pups are born with white coats. They can be found on both sides of the North Atlantic Ocean.


Gray Seals have large colonies on the coasts of the United Kingdom, Ireland, Newfoundland, Quebec, Sable Island and New England. They're fairly large animals, with adult males measuring almost 11 feet long (3.3 meters) and weighing up to 680 pounds (310 kg). Females are smaller, measuring just under 7 feet (2 meters) in body length, and only 420 pounds (190 kg) in weight. Western Atlantic seals tend to be much larger than their Eastern cousins. Gray Seals are sometimes mistaken for Harbor Seals, but a few characteristics (a straight skull profile, larger and fewer spots on their coats, and wide-set nostrils) allow observers to distinguish the two species.

The diet of the Gray Seal varies greatly and depends on what's available, but in general it includes a variety of fish species (cod, skates, herring, gadids, flatfish), as well as crustaceans and cephalopods. While hunting and foraging, they will typically dive to depths of 100 to 230 feet (30 to 70 meters). Bigger animals have been known to grab seabirds and infant porpoises. The average intake is about 11 pounds (5 kg) of food per day, but they do not need to eat every day and both males and females will fast during the breeding season.


Autumn is when female Gray Seals will start to gather at the pupping sites, forming rookeries. Males will compete with each other for the right to mate with a group of (usually 10) females, and if they establish their dominance over the other males, they will be the only ones to mate with those particular females that season. Total gestation is about a year, which means that the previous season's pups are also born in the autumn. They shed their white pup coats within about a month, suckling the fat-rich milk from their mothers while they grow big enough to enter the water for the first time with their brand-new coats.


Gray Seals have a generally healthy population, being considered a species of least concern by the IUCN. Regulations were passed on both sides of the Atlantic during the 1900s to prevent the Gray Seal from reaching low population numbers, and since then they have thrived. They have become particularly numerous on the western side of the Atlantic and the coastal communities of New England and Canada, which has lead to calls for population control in the form of a cull.

Share This Story