Scientific name: Halichoerus grypus
Family: Phocidae
Size:: male: 2.70 meter; female: 2.00 meter
Weight: male: 310 kilos; female: 190 kilos
Habitat:North Atlantic Ocean to the Baltic Sea
Endangered status: not endangered

The grey seal has an elongated snout. This is flat from the forehead to the tip of the nose. This makes them a bit like a "real" dog. In addition, the adult males have a very bulbous nose, which is especially striking when you look at them from the side.

Did you know...

The nostrils of the grey seal are large, round and set wide apart. They do not run towards each other, but are straight apart. This has no other seal species and it gives grey seals a sort of pig nose. That's where their scientific name of the grey seal, Halichoerus grypus, comes from which means: "hook-nosed sea pig".

It is a fairly large seal species. An adult male living in the seas of Europe grows to about 2.7 meters in length and can weigh up to 310 kilograms. Adult females are much smaller. They grow to about 2 meters in length and weigh up to 190 kilos. Grey seals in the western Atlantic tend to be quite a bit larger. They sometimes grow up to 3 meters in length and can weigh up to 400 kilos.

Did you know...

Males are much larger than the females. They usually have a much thicker neck than the females (often with scars from fighting with other males). In addition to size, there are major differences in appearance between males and females in grey seals. The term used in science for this is sexual dimorphism.

They also have a different colour. Adult males have dark brown to black fur with some light spots here and there. The females are much lighter brown or blonde in colour, with dark spots. If a seal's fur is completely black, it is called melanism. This is pretty rare.

Grey seals live in groups on the coast of the Western Atlantic Ocean in the Northern hemisphere through to the Baltic Sea. The seals of the Atlantic Ocean have probably had no contact with the seals that live in and around the Baltic Sea for thousands of years. That is why we also speak of two “subspecies”. Each of these species has its own scientific name.

• Halichoerus grypus atlantica (in the Atlantic Ocean)
• Halichoerus grypus grypus (in the Baltic Sea)

They are usually found on rocky shores, beaches, sand banks, islands and even - far enough north - on ice floes. Grey seals share their habitat with many other animal species, for example the common seal (Phoca vitulina).

Grey seals have been an endangered species for many years. Due to centuries of hunting by humans, grey seals had completely disappeared in some areas of the world. In the Netherlands, this species had been gone for hundreds of years before they came back in the eighties. In most of Europe they are still a protected species.

Did you know...

In the Netherlands, grey seals can be seen along the entire coast. Most are in and around the Wadden Sea. A smaller group of seals live in the south of the country, in Zeeland. Here, too, they share these areas with common seals.

The grey seal here is doing better now. In 2021, there were 6,788 animals in the Netherlands. This is almost twenty percent more compared to the previous year. There are more and more grey seals worldwide. According to the 2016 IUCN Red List, there were approximately 316,000 adult grey seals. They therefore have the status "not endangered", this is mainly because they are a protected species in many countries.

Grey seals eat anything. Depending on where they live and which prey is most present at that time. They're not that p. They eat Atlantic fish species, squid and crustaceans. A few grey seals have also been seen eating birds or even young seals and porpoises.

When looking for food, they usually dive for 4 to 10 minutes, but sometimes they search for up to 30 minutes. While the average dive goes to a depth of 60 to 100 meters, dives have also been measured from 200 meters deep.

Like other seal species, grey seals only search for food. Although grey seals often rest in large numbers on the coast in some places, they are not seen as very social animals. They usually try to avoid social contact. Except when females feed their pups or during the mating season.

Here in the Netherlands, there are not really large groups of grey seals. They rest in smaller groups on sandbars or beaches. Every year at the end of spring, larger groups of grey seals come together to molt. They then lose their winter coat. They are then a few weeks more on land. On land, they lose their hair more easily. And on top of that: the sunlight is good for the new coat.

The female is ready to mate a few days after giving birth. During the mating season, adult grey seals gather on shore or on pack ice to reproduce. The males then compete for females. They do not defend a territory or harem like sea lions. Instead, they fight other males to mate with certain females.

Although their fights seem vicious, grey seals don't fight to the death. Usually, they don't get hurt very badly. Instead, they fight until someone is too tired or realizes they've lost. The strongest males can mate with up to 10 females.

The fertilized egg is not moved to the uterus until three to four months after the moment of fertilization. This is called diapause. After that, a grey seal is eight months pregnant. In the time between fertilization and pregnancy, the female must gain a lot of weight. So when her new pup is born, she can take good care of it.

Did you know...

Grey seal pups are born in winter. Female grey seals give birth to one pup on land or ice. Pups weigh between 11 and 20 kilos at birth and have a white coat in the first few weeks. We call this baby coat “lanugo”. It sometimes takes up to three weeks for the puppy to lose all its white hair, but it usually disappears within a few days.

The nursing period lasts about three weeks. During this time, the pup will gain four times its weight. This is due to the fatty breast milk, which contains approximately 43% fat in grey seals. Because the female has to stay with her pup a lot, she has little time to eat and she loses a lot of weight. Female grey seals sometimes weigh as much as 40% less after this period.

After 3 weeks of nursing, the mother has no breast milk left. She leaves her pup and is not coming back. The first few days the pup will stay on land, because the lanugo coat is not suitable for swimming. The pup will not eat. They then begin to lose the white fur and lose weight until they are finally ready to enter the water.

Then they learn to hunt for themself. Without help from the mother: natural instinct takes over. It is not for nothing that the grey seal is the largest predator in the Netherlands.

Scientific name: Erignathus barbatus
Family: Phocidae
Size:: 2 - 2,5 meters
Weight: 250 – 300 kilos
Habitat:: Arctic
Endangered status: not endangered

Do you know how the bearded seal got its name? Bearded seals have a bunch of thick and long whiskers. When these are dry, the ends of these whiskers curl. It looks like they have a thick moustache.

Bearded seals have a broad head that appears a bit flat when viewed from above. Their eyes are relatively small and close to eachother. They have a large, broad muzzle with the cheeks appearing to droop a little. Their nostrils are wide apart and quite large^1,3.

The head is quite small in relation to their body. Bearded seals have a large, long body. Adult animals are between 2 and 2.5 meters long, with an average weight between 250 and 300 kilograms³.

The females sometimes grow a bit larger than the males. But otherwise the females and males are difficult to tell apart. They both have a gray-brown color, sometimes with a rust-colored head and flippers. Because their fingers are all the same length, bearded seals' flippers appear almost square in shape. The nails are wide and short^1,2.

Did you know...

Bearded seals are members of the family true seals (Phocidae), and belong to the subfamily of northern true seals (Phocinae). They live in the Arctic. Their remote habitat and way of life make it very difficult to conduct long-term research. As a result, little is known about their behavior.

This seal species has two subspecies. The Eastern bearded seal (Erignathus barbatus barbatus) and the Western bearded seal (Erignathus barbatus nauticus). The first one lives in the Atlantic part of the North Pole. The Western bearded seal also lives in the North Pole, but on the Pacific side¹.

It is estimated that there are more than 500,000 bearded seals. They are considered non-threatened, but global warming is causing significant changes in their habitat¹. They depend on sea ice during mating season, so its reduction is disadvantageous to the bearded seal population. So they are not in trouble yet. But melting ice caps will mean less and less space for bearded seals to mate and nurse pups².

Bearded seals mainly hunt benthos. Benthos is a collective name for organisms that live in and on the seabed. Their diet is varied. They eat crabs, shrimps, shellfish, squid and fish. They prey on these animals in shallower waters, usually diving around 100 meters deep. Younger, less experienced animals sometimes go a lot deeper (up to 450 meters). Bearded seals can stay underwater for 25 minutes, but most dives don't last more than 10 minutes3.³.

Bearded seals are not very social. They prefer to spend their time alone. Females also like to be alone when they have and nurse their pups. However, it is not strange to see them lying next to each other on the ice. They prefer not to go into the water during moulting. Then they can often be found in small groups on the ice.

Bearded seals rest close to water. They do this so that they can flee quickly if necessary. So the best places to rest are along the water's edge on the pack ice, on ice floes or around breathing holes on the sea ice³.

Did you know...

Little is known about this species, both about mating behaviour and about the period of birth. For example, we don't know how long the pregnancy of bearded seals lasts.

When they are between 5 and 7 years old, bearded seals become sexually mature. That means that they are adults and can therefore have pups.

Bearded seals mate in the water. Because of this, little is known about their mating behaviour. We do know that males “sing” during the mating season. They do this to attract females and to scare off other males. Their singing usually consists of sharp, whistling sounds. These start very high and then become lower in pitch³.

The pups are born between March and early May on ice floes in shallow water. The pups are around 1.30 meters at birth and then weigh an average of 35 kilos. They have dense, light gray fur and a layer of subcutaneous blubber.

Did you know that most bearded seal pups enter the water with their mother within a few hours of birth? They probably do this to avoid polar bears in the area³.

During the nursing period, the pup spends about half of the time on the ice sleeping. The rest of the time, mother and pup will be in the water together. So bearded seal pups learn to swim and dive from their mother, something most other seal species do not do³.

The milk that the pup gets from the mother is about 50 percent fat. This helps the pup gain weight quickly. The nursing period lasts between 18 and 24 days. At the end of this period, the bearded seal pup can weigh 100 kilos. So pups gain 60-70 kilos in this short time! The mother then leaves her weaner to mate^2,3.

Bearded seals are often on the menu of polar bears. Orcas, Greenland sharks and even walruses also sometimes hunt young bearded seals.

These seals are also hunted by humans. Traditional seal hunting is an important source of food, fuel and equipment for native people.

Bearded seals were also hunted commercially in Russia. Between 1950 and 1960, more than 10,000 bearded seals were killed. That has now been greatly reduced. Now only a few hundred animals are allowed to be killed each year. However, the only sources on this are from the Russian government, so it is not clear whether these numbers are correct and whether those rules are also being followed^3,4.

¹ (Shirihai & Jarrett, 2021 [2006])

² (NOAA, 2022)

³ (Kovaks, 2018)

⁴(Cameron et al., 2010)