All information about the gray and harbor seals

The grey and harbor seal

All animal species are divided into families. Seals or seals are a family of marine mammals consisting of as many as 19 different species. Of the 19 species of seals worldwide, two live in the Wadden Sea:

• Harbor seal

• The gray seal

In the wild, a seal reaches a maximum age of 25 years. But at the shelter in Texel you will also find seals that are more than 30 years old. Seals make a cute impression with their big, black eyes and sweet nose with thick whiskers. But don't be fooled! Seals are predators with sharp teeth and a big appetite for fish.

What does a seal look like?

A bacon layer for warmth and food reserves
Seals have short, stiff hair and almost no undercoat. Instead, they retain their body heat with a layer of bacon, sometimes more than 5 centimeters thick. This protects them from both heat and cold. Another important benefit of this bacon layer? The seals always have a food reserve. This is handy for when they don't get food so easily for a while. For hunting, they use their tactile hairs in the mustache and eyebrows. These are well developed, allowing them to sense their surroundings well and find their prey easily.

Differences between common seal and gray seal
Most species of seals have brown to gray mottled fur. In seals, this is also called a fur. The harbor seal and the gray seal look much the same, but differ mainly in the shape of the head. In the common seal, the nose is slightly bent inward and the eyes face forward. The gray seal has a straighter and longer nose, giving the head the shape of a cone. Also, their eyes are a little more to the side. Furthermore, you can tell the difference between the two types of seals by the position of the nostrils. In a common seal, these have a v-shape with curved ends, while in a gray seal they are upright.

Smooth through the water
Both species of seals have streamlined bodies, which allow them to move smoothly through the water. This means there are no ears, sex organ or tail sticking out. Everything is hidden under a thick layer of bacon and skin. And although seals do not have auricles, they do have ears. These are holes located diagonally behind their eyes. Furthermore, seals have a total of four flippers, with flippers between the toes. A seal also has teeth with sharp teeth, which it uses to catch and eat fish. Gray seals generally grow larger than harbor seals. In both species, males are larger than females.

Where do seals live?

A tasty spot for seals
Both seal species are mostly found in areas with low tides. Here the ground falls dry all the time, only to flood again. Seals find this a wonderful place to laze around. They are also often found near ice floes, because they can lie down and rest there as well. Of the approximately 11,000 seals in the Netherlands, about 90% can be found in the Wadden Sea. Other populations live in the Eastern and Western Scheldt, among others. You hardly see them in Belgium because the coastline there is tighter than in the Netherlands.

Different habitats
In our country, you mainly encounter the common seal. Also worldwide, the habitat of the common seal is larger than that of the gray seal. The grey seal lives mainly in areas between Europe and North America, where temperatures are moderate. The common seal can also live well in colder areas. Thus, you find this species between Asia and North America and further north.

Safety first
Seals are solitary animals. That means they prefer to be alone. So why do you often see them in groups on land? They do so because it is safer. With more seals, they are more likely to notice possible danger. Seals also usually lie close to the water, so they can flee quickly if they don't trust something.

Reproduction and pups

Fighting for a female
In both species of seals, a male usually mates with several females. To do this, the males fight each other, with the strongest usually winning. But sometimes a male is impatient and already wants to mate when the female is not yet ready. Then he is rejected and a less strong male still has a chance. Common seals usually mate in the water, while gray seals more often mate on the beach. In addition, seals are mammals. This means their pups fully develop in the mother's belly.

Grey seal pups: cute but clumsy
Gray seals are born in winter and therefore have thick winter fur. With these thick, white hairs, the seal pups look endearing. Unfortunately, it is a bit awkward: they cannot swim with it. Therefore, they stay on land for the first few weeks. The mother visits regularly during the first two to three weeks to give the pup milk. During this time, the pups only receive milk and do not yet learn to eat fish.

Common seal pups go directly into the water
Common seals are born precisely during the summer months. Females can give birth on average from the age of four, while males are fertile on average only from the age of six. The young are born when the water is low, on dry sandbanks. That means they have to swim almost immediately, as soon as the tide comes in. Up to three weeks after birth, the pup drinks milk from the mother. The mother's milk has a fat content of 45 percent, making it incredibly nutritious. Consequently, the pups grow considerably and go from 10 pounds to about 24 pounds in a short time.

The daily life of a seal

What do seals eat?
Seals eat mostly fish. They use their whiskers to detect fish and other marine animals in the water. This is because they can use them to sense the tiniest movements, so seals know exactly where their prey is even in murky water. They can do this up to a distance of up to 100 meters! In addition, they can also sense at a distance how big the fish is and what shape it is. Seals do not have a strong preference for one type of fish. They mainly catch fish that live close to the bottom, but also eat other marine animals, such as squid, shrimp and crabs. Seals eat an average of about 4.6 pounds of fish per day. As a result, they eat 43 percent of the fish in the Wadden Sea, and in the shallow coastal zone of the North Sea it is as much as 60 percent.

Howling seals
During the suckling period, seal pups make a very distinctive sound. In the Netherlands, we call this "howling" and seal pups are also called "howlers. But this actually gives the wrong impression. Seal pups actually make this sound to distinguish themselves from other pups in a large group. This way, the mother knows which pup is hers and the pup can clearly indicate that it needs milk. In addition, seals make other sounds later in life.

In the sea and on land
Seals are completely adapted to life underwater. With their large, dark eyes, they see very well under water, and they can easily reach speeds of up to 35 kilometers per hour. They are also called the acrobats of the sea. On land, they appear a lot more clumsy. They see a lot less well and only just reach a speed of 2 kilometers per hour. Yet you see them regularly above water. For example, they like to rest in the sun, on a sandbank or on the beach. are the acrobats of the sea, but on land they come across as rather clumsy. Although they dash through the water at 35 kilometers per hour with ease, they only just manage 2 kilometers per hour on dry land. With their beautiful, large eyes, seals can see well under water, but above water they would actually need glasses. So seals are completely adapted to life underwater. Still, you can regularly encounter them above water. They like to rest in the sun on a sandbar or the beach.

The seal is a real water rat
While swimming, the seal uses its body and rear flippers to gain considerable speed. With the front flippers, he determines the direction. Seals can also dive incredibly deep. They actively swim down for the first few minutes, after which they sink further into a "glide. In doing so, they go hundreds of meters into the depth. Wondering how they still keep enough oxygen in their bodies? First, the blood of seals can absorb much more oxygen than that of humans. In addition, a seal can regulate its heartbeat and breathing. That way, he can stay underwater for up to half an hour!

Ranger Robert shows you how the seals are fed in a Ranger Request.

Threat to seals

The Netherlands has a troubled history when it comes to seals. In the past, for example, we hunted seals in the North Sea area for a long time. We saw them as harmful animals that competed a lot with fishermen. The seals damaged the nets and hijacked the fish in front of the professional fishermen. Hunters therefore received a premium for each seal shot. Seal fur was also used to make clothing. Fortunately, seal hunting in the Wadden and North Seas has stopped for nearly 50 years and seal numbers have grown again. Yet seals are still threatened. For example, the animals still suffer from disturbances caused by shipping, trash and tourists.

Conservation

Fortunately, the seal's status is safe. But unfortunately, many of the species you see in our park are endangered and struggling in their native habitats. Did you know that worldwide more than 4,000 animal species threatened with extinction are endangered? Together we can help them, with big, or small steps. Want to know how? Then click here.

Interesting facts about seals

• Seals can imitate sounds and even words.

• Seals do not drink salt water, but get fresh water from the fish they eat. Therefore, when they can find little food, they have to be extra careful with their water. That's why they hold their pee longer.

• Young seals must teach themselves to catch and eat fish. Their mother does not teach them how to fish. Young seals therefore often lose a lot of weight in the first period after the mother's milk stops. If they do well, they learn to catch fish better and better.

• Seals always have cold feet.

• Seals look cute and love to lounge around. Yet they are the largest predators in the Netherlands and are even at the top of the food chain. Their only enemy is humans.

Difference between seals and sea lions

In a Ranger Request, Ranger Floor explains 5 recognizable points where you can easily tell seals and sea lions apart.

Come see the seals in real life!