Germanys major carnivore
Since the mid-nineties, grey seals (Halichoerus grypus) started to repopulate the German North Sea area. The isle „Düne“ near Helgoland is popular among the seals. Although it is a major haul-out site year-round, most animals gather there during pupping and breeding season in winter and during moult in spring.
Grey Seals in the Wadden Sea
There are currently about 5,445 grey seals (Halichoerus grypus) in the Dutch, German and Danish Wadden Sea. Of these, around 1,179 are situated in the Wadden Sea of Schleswig-Holstein. The worldwide population amounts to about 230,000 individuals, which are separated into three populations distributed along the coastline of the North Atlantic and the Baltic Sea.
Grey seals differ from common seals in their head and teeth shape: Grey seals have a conical, large head and conical teeth (the origin for the German name “Kegelrobbe”)
Grey seals show pronounced gender dimorphism, which means that males and females greatly differ in appearance and height. Adult male grey seal may reach a length of 230 cm (7 ft 7 inches) and weigh up to 350 kg (772 pounds), essentially larger and heavier than male common seals of the same age. Female grey seals are smaller and lighter, reaching a length of 190 cm (6 ft 3 in) and weigh up to 150 kg (331 pounds). They can be distinguished by their fur pattern as well: males have a dark coat with light spots. Females have dark spots on a light coat.
Grey seals give birth to their pups in winter. The exact time varies depending on the area of distribution. In the Wadden Sea the main birthing period of time for giving birth is November to January. The newborn grey seals have a white, long embryonic fur, which protects them from the cold. They are capable of swimming right after birth but they avoid the cold water of the North Sea during their first weeks because their embryonic fur would soak up the water, and could not serve its purpose anymore. Since grey seal pups are nursed for only 2 to 3 weeks swimming would only be a waste of energy. Due to those reasons they are born high up on the beach, or even in dunes. The mother returns frequently in order to nurse them. She recognizes her own pup by its particular voice and smell. Grey seals are born with a weight of 10 to 15 kg (22 to 31 pounds). After being nursed for about 20 days they weigh about 50 kg (110 pounds). The pup remains out of the water even after the mother has left it until the fur change – which sets in around the time the mother leaves – is mostly complete. During the fur change the lanugo is replaced with a short fur, similar to that of adult animals. Undisturbed areas where they can rest and which will not be flooded by a high tide are essential for the survival of grey seal pups.
Grey seals reach maturity at the age of 4 to 7 years but they are not fully grown until they are at least 10 years old. They may become 45 years of age. About one month prior to the date of birth both, males and females, gather at the area where females will give birth. The strongest males stay in a particular distance from each other and weaker bulls get chased away. After the females give birth to their pups the bulls start marking off real territories and defend them from rivals.
The animals rarely eat during the time of reproduction and therefore lose a lot of weight. Nevertheless, they are able to compensate until after their fur-change during which they spend long times out of the water. Females change their fur in February, males begin to moult in March. Grey seals mainly nourish upon fish. Their diet contains a high number of different fish species like cod, eel, salmon and flat fish but also occasionally shrimp and mussels.
In Schleswig-Holstein grey seals can be seen mainly on Helgoland, but also near Sylt and Amrum. Within the last years the isle “Düne” near the island Helgoland has become an important resting area and a place to give birth to pups. By frequent guided tours and closings of beach areas when necessary, it is guaranteed that the animals are not disturbed. Due to this, grey seal howlers (pups that are seperated from the mother animal permamently) are less prevalent. If however a grey seal pup has been decalared as howler, it is brought into the Seal Centre Friedrichskoog.
For further information, please feel free to contact the Seal Center Friedrichskoog