Grey Seals: Profile and Information

Grey seals can be found on both coasts of the North Atlantic Ocean.

It is part of a large family of seals known as Phocidae, generally called “earless seals” or “true seals.”

Grey seal is the only species categorized in the genus Halichoerus.

It is also recognized as the Atlantic seal or the horsehead seal.

Scientific Classification

Physical Appearance

A male grey seal in the eastern Atlantic population is about 1.95 – 2.3 m (6 ft 5 in – 7 ft 7 in) long and weighs 170 – 310 kg (370 – 680 lb). While a female grey seal is much smaller, it would naturally measure up to 1.6 -1.95 m (5 ft 3 in – 6ft 5 in) long and weigh about 100 – 190 kg (220 – 420 lb).

Individual grey seals from the western Atlantic are often more massive, with the males’ size measuring up to 2.7 m (8 ft 10 in) and weighing about 400 kg (880 lb).

The females have an average size of up to 2.05 m (6 ft 9 in) and occasionally weigh up to 250 kg (550 lb). A record-sized bull grey seal can reach up to 3.3 m (10 ft 10 in).

Wintering hooded seals can be taken for grey seals due to their similar size and share a large-nosed appearance to some degree. However, the hooded seal has a paler base color and usually displays more obvious spotting. 

Grey seals lack outer ear flaps and particularly possess broad snouts. Bull Greys have more prominent noses and a slightly curved shape than ordinary seal bulls. Male seals are typically shadier than females.

The male has brighter patches and blemishes around their neck. Meanwhile, the female seal is silver-grey to brown with dull patches.

Habitat and Distribution

In the UK and Ireland, the grey seal breeds in various colonies on and around the seashores. Predominantly, huge colonies can be found in several places that may, including the Blakeney Point in Norfolk, the Farne Islands off the Northumberland Coast, Donna Nook in Lincolnshire, Orkney, North Rona, and many more.

Around the Western North Atlantic, grey seals are commonly seen in vast numbers in the seaside of Canada & south to Nantucket in the US. In Canada, it is generally found in regions such as the Gulf of St. Lawrence, the Maritimes, Newfoundland, and Quebec.  The biggest colony in the world can be located at Sable Island, NS.

Throughout the winter, grey seals can be found hauled out on rocks, shoals, and islands close to shore. Occasionally, they come to the coast to rest. In the spring, newly weaned pups and yearlings sometimes get stranded on beaches after becoming isolated from their group.

Grey seals are weak to natural predators. Large sharks are known to hunt grey seals in Canada, especially great white sharks and Greenland sharks. In Great Britain, grey seals are usually a common target for killer whales. Grey seal pups are occasionally carried alive by white-tailed eagles, as well.

Feeding

The grey seal feeds on a wide assortment of fish, primarily benthic or demersal variety, and these fishes are snatched at depths down to 70 m  or more. Sand eels are an essential part of their diet in several localities. Cod and other aquatic animals like gadids, flatfish, herring, and skates are also crucial locally.

Nevertheless, the grey seal will eat whatever is accessible, including lobsters and octopus. The standard customary food requirement of a grey seal is calculated to be around 5 kg. Grey seals don’t eat every day and run fast during the mating season.

Recent studies from Scotland have shown that grey seals will also hunt and feed on big animals such as harbor porpoises and seals. In 2014, a male grey seal in the North Sea was recorded and filmed weekly, slaughtering 11 pups of its species.

Related wounds on pups’ bodies were also found in the same region. This suggests that infanticide and cannibalism might not be unusual in grey seals. Male grey seals could participate in such behavior to improve reproductive success via access to easy targets without leaving the prime habitat.

Communication

While it was initially known that marine mammals express themselves vocally, a new study performed by researchers at Monash University reveals that grey seals clap their flippers as a different kind of communication.

They clap their flippers underwater to prevent a predator from attacking them. During the breeding season, the clapping can locate a potential companion.

The Monash researchers also indicate that seals are generally known for clapping, so this behavior might not be new. However, the applause recognized usually occurs in captivity. Clapping seals are linked to aquariums and zoos but were never examined in the wild for this action.

Reproduction and Mating

Grey seals are top breeders because they feed to build up stocked fat, which is used when nurturing their pups. During this period, searching for food is out of the question.

They deliver a single pup each year, with females’ conceptive years starting as early as four and can range up to 30 years of age. It has been noticed that female grey seals provide all parental care.

Throughout the breeding season, the male grey seal doesn’t provide parental care but protects females against other males for mating. The pups are bred at around a mass of 14 kg. They are born between September – December in the eastern Atlantic and between January – February in the west, with dense, silky white fur.

Grey seal pups are precocial, with the mothers returning to the ocean to feed once separated from their pups. Pups also experience post-weaning soon before abandoning land and learning to swim.

Within a month or more, they take off their pup fur, grow thick, waterproof, grown-up skin, and migrate to the sea to learn to fend for themselves.

Seal pup initial year survival rates are estimated to range from 80 – 85% to below 50% based on locale and situations. Starvation seems to be the leading factor of pup death because of the difficulties in learning to feed.

Seals usually haul out to rest or ingest their food, so if you encounter one on a seashore, give it a lot of space and keep your dogs away. This is because seals can easily get frightened from their rocky resting places.