In December, extraordinary phenomena occur on Helgoland, Germany's only offshore island: the grey seals (Halichoerus grypus) arrive on the Düne, the sandy neighbouring island of Helgoland. It is the depths of winter, stormy and rainy - and precisely now, during this cold season, the grey seals give birth to their young.
Our team visited the island to attend a seminar on Germany's largest predators, the grey seals, led by Dr Leonie John, a biologist and director of the Naturakademie Jordsand. Before setting foot on the Düne, the team was instructed that grey seals must not be touched and that a safe distance must be maintained. These rules are established and strictly monitored. However, the prohibition of contact (meaning a 30-metre distance) and the simple advice that a large telephoto lens is only necessary if one wishes to photograph individual whiskers, did not prepare us for what lay ahead. It was indeed a close encounter with the grey seals, requiring humans to retreat instead. Approximately 800 animals lie scattered everywhere, some directly on or adjacent to the paths.
The pups are born with fluffy white lanugo fur and are nursed by their mothers for two to three weeks. Seal milk contains 50 to 60 percent fat, allowing the pups to grow rapidly from a birth weight of approximately 12 kilograms to 45 kilograms. Around the fourth week of life, the pups are weaned and left to fend for themselves. During this phase, the young seals shed their white lanugo coat. The mother mates again with a bull on the beach and, significantly emaciated, returns to the sea. Once the moult is complete and hunger drives the young seal, it also finds its way into the North Sea, where it must hunt and survive independently from the very beginning.
Grey seals are Germany's largest carnivores and are protected under strict conservation laws. They are the apex predator in the North Sea and absolute opportunists. This did not protect them from being driven to near extinction by human hunting. Populations have only recovered since the implementation of conservation measures, such as the hunting ban imposed in the North and Baltic Seas in 1988. The breeding colony of grey seals on the Düne near Helgoland is a prime example of how effective and successful conservation can be when animals are granted the necessary space and human interference is minimised.
The Verein Jordsand contributes to building understanding for these marine mammals through its population counts and educational seminars. Our team experienced an informative and fascinating weekend with Leonie John and her team.
Profile of the grey seal (Halichoerus grypus):
Weight: 250-330 kg
Length: 2.8 m (m); 2.3 m (f)
Pelage: Ground colour with spots, dark with light spots (m), light with dark spots (f)
Parallel, II-shaped nostrils
Lifespan: 25-30 years (m), 30-35 years (f)
Diet: Fish, molluscs, and other marine mammals
Moulting period: February-March
Reproduction / Births: Nov.-Jan. on land
Mating: Immediately following birth and lactation
Locomotion: Speed approx. 20 km/h on land, approx. 30 km/h in water.
Dive depth: Up to 140 m, dive duration up to 20 minutes
