By Peter Balwin
Around the North Pole lives an animal that has always appealed to man – for better or for worse. Yet Central Europeans have known this arctic character animal for only five hundred years. Many who have had the privilege of facing this animal at least once in their lives still encounter it today with an indefinable mixture of curiosity, aversion, fascination and perhaps a little bit of reluctant shuddering: the walrus!
The largest seal in the northern hemisphere was not given any laudable attributes from the very beginning of its contacts with European seafarers in the 16th century. The first impression of a walrus is “not a favorable one”, Alfred Brehm himself knew to report in the 1870s in his famous “Thierleben”. The “oceanic monster pig” or “sea cow” wore “spiky brushes around its oxen’s mouth” (1671) and really stimulated the imagination of the explorers of the time. The “seahorse with two long, protruding teeth” (Holland, 1578) “climbs with its teeth to the tops of the rocks, from where it rolls back into the sea – if it does not get stuck on the rocks, surprised by sleep,” (Olaus Magnus, 1539).
Until the end of the 16th century, hardly anyone in our country had ever seen a real walrus – or recognized it as such. The distinctive tusks of this giant seal, on the other hand, have been coveted trade objects since the 9th century. For example, in 1282 the Viking bishopric on Greenland paid its tithes to Rome in ox hides, sealskins and – walrus teeth. In 1520, a bishop in Trondheim, Norway, wanted to look particularly good by not only delivering the walrus’s teeth to Rome, but also by shipping the entire salted head to Pope Leo X. The bishop’s order to deliver the walrus’s teeth to Rome was also a good one. That walrus head, en route to the Holy City, was transported via Strasbourg, where Albrecht Dürer masterfully sketched it, thus providing the inquisitive people of Europe with a usable representation of this “monster” for the first time.
Seeking a faster route to the Spice Islands in the Far East, more and more European expeditions set sail in the 16th and 17th centuries and set course for the Arctic. However, they did not yet find the longed-for passage to Japan. But each of these often tragic voyages lifted the veil of the unknown over the Arctic more and more. Stories of new islands, strange people and strange animals reached the merchant masters in Europe. And the first captured “whale horses” found their way repeatedly and involuntarily to the astonished aristocrats, the first demonstrably in 1608.
At that time, however, it was not the walrus that excited the commercial councils, navigators and companies, but the report of Arctic seas that seemed to be seething with whales. The hunt for whales around then-Spitsbergen and Greenland was thus considered open, with the well-known tragic consequences for whale populations that we can still clearly perceive today, 400 years later. It was only when there were soon no more whales to kill that people turned to other species of necessity – and the walrus came into the sights of the merciless seal hunters.
“They are caught for their teeth alone,” admits Friderich Martens in his 1671 travelogue. And further he writes: “When the Wall Ross is killed, they cut off its head, the body they leave lying or let it float in the water. They take the head with them to the ship, where the teeth are cut out; the two large teeth belong to the owners or merchants of the ship, and the small grinder teeth are little acknowledged.
The tooth walker as a target
The greed for these two tusk-like elongated upper canines nearly sent the walruses into extinction. These teeth provided the ivory coveted from time immemorial for carvings, which was sought after for centuries, which is why the walrus remained high on the hunting list of European and North American businessmen. It is estimated that there must have been many hundreds of thousands of walruses in North America and the European North Polar region before Europeans discovered the New World.
In the late 18th century, when whaling came to an end, commercial hunting of walruses began. Not only the ivory of the tusks was in demand. Walruses with their layer of blubber up to ten centimeters thick supplied oil. And also the two to four centimeters thick skin was utilized; among other things one made from it driving belts for machines; sixty or more men could pull on a walrus leather belt without tearing it, it says in a document from the 13th century.
The slaughter took on monstrous proportions. By the mid-20th century, the entire population of the Atlantic walrus(Odobenus rosmarus rosmarus) had been nearly wiped out in every corner of its range. Legislation to protect this distinctive seal in the various Arctic states came almost too late. The Russians were the first to recognize the seriousness of the situation and issued hunting regulations as early as 1921, which were extended in 1956, so that since then only the indigenous people of Russia, for whom hunting is the basis of life, are allowed to pursue walruses there to a limited extent.
The same is true for Greenland, on whose wild east coast a complete ban on walrus hunting was imposed in 1956. Despite this, 20 to 30 of these animals are still shot every year. On the west coast of Greenland, however, sustainable hunting is allowed for locals. Canada followed suit in the early 1930s, and in Alaska hunting is now reserved for Native Americans (American Indians, Aleuts and Inuit).
On Svalbard, these animals have been fully protected since 1952, when it became clear that just about a hundred walruses had survived the slaughter there at that time.
Apart from those walruses that still become hunting victims of the indigenous peoples, the primitive “toothed walker”, as Odobenus is called in Greek, can now finally rest unconcerned on the beaches of the icy coastlines. For a good three quarters of a century, the representatives of the two walrus subspecies, the Atlantic and the Pacific, have been more or less protected.
And now humans realize that we don’t even know everything about this animal, which has been persecuted for so long, from its exciting life. Yet the first walruses were already cavorting in the waters of the early Miocene 18 million years ago. About 2,000 years ago, the walrus was part of the normal fauna of the North Sea, where, nota bene, it still strays back from time to time: from the 20th century, there are a good half dozen reported walrus observations from the North Sea. A young female walrus is considered to be the last visitor from the Arctic so far. It was first discovered at the beginning of September 2021 on the island of Baltrum in the Wadden Sea of Lower Saxony and from there began a regular “island hopping”, because the young walrus was sighted on four more North Sea islands in September alone.
While zoologists – had they existed at that time – would have been able to distinguish 13 species of walrus in prehistoric times, only 1 species occurs today, the walrus, or Odobenus rosmarus. However, experts distinguish two subspecies whose separation dates back a good 500,000 to 785,000 years and whose physical differences are recognizable even to laymen.
First, there are the 20,000 to 30,000 individuals of the Atlantic walrus(Odobenus rosmarus rosmarus) of “our” region. Its habitat ranges from the central Canadian Arctic through Greenland and Svalbard to the Russian Kara Sea east of Novaya Zemlya. While the 3.5 meter long males weigh up to 1,500 kilograms, the females with their body length of 2.5 meters and a weight of 700 to 900 kilograms seem downright dainty. Even further east on the northern coast of Siberia, one encounters the Laptev walrus(Odobenus rosmarus laptevi), which is sometimes cited as a third subspecies.
On the other hand, in the Bering Strait region between Russia and Alaska live about 200,000 animals belonging to the subspecies of the Pacific walrus(Odobenus rosmarus divergens). They are noticeably larger than their European relatives. A male there reach weights of 1,700 kilograms and reaches a body length of 4 meters. Also the teeth are longer with the Pacific walrus and appear therefore nicely bent apart or turned apart (lat. divergens). Typical of this subspecies are the photos that we have all seen somewhere: Wide beaches, of which you actually see nothing – because every square meter is occupied by a fat, pink walrus and thousands of these animals crowd into the picture.
Wagging while eating
Walruses feed mainly on rather small creatures of the seabed (the benthal). For example, benthic invertebrates such as bivalve molluscs (for example, hiatellidae, also called the northern rock driller in German) are at the top of the menu. Squid, polar cod, worms, crabs and amphipods, sea cucumbers – and the occasional ringed seal – provide variety on the menu.
However, nothing beats the beloved mussels. It is estimated that a walrus consumes an average of 6.2 percent of its body weight by eating benthic invertebrates. This means that a walrus weighing 1,000 kilograms has to eat 180 to 240 kilograms of mussels every day to get the necessary daily ration of 60 kilograms of soft mussel meat. For this purpose, a walrus must track down between 4,000 and 6,000 mussels per day. Taking this underwater arithmetic a bit further, we get the astonishing figure of 8,900 tons of food that the entire population of Pacific walrus in the Bering Sea region alone devours every day – or 3.2 million tons per year.
Because the meals are hidden in the uppermost, muddy layers of the seafloor, a walrus has to kick up quite a bit of dust to get to its lunch. The walrus’ search for food at the bottom of the sea therefore incidentally leads to large amounts of the upper sediment layer being heavily plowed up. This, in turn, could be a major contributor to a powerful boost in productivity in walrus feeding areas as plowing releases nutrients. Without the walruses’ intervention, these substances would remain trapped in the bottom silt.
Once at the bottom of the sea, the walrus brings into play another feature of its rustic appearance, the tactile bristles on its nose, also called vibrissae. 600 to 700 such hairs – more than in other seal species – adorn a walrus snout and give the animal its typically unshaven appearance.
These bristles are actually delicate organs, each one supplied with nerves and blood vessels and attached to small muscles. So walruses can move them in groups and use these tactile hairs to detect the shape and size of their prey. Thanks to film recordings by scientific divers off East Greenland, it was possible a few years ago to prove for the first time how a walrus gets its food.
An astonishing result of this research project: walruses tend to use mainly the right front fin during foraging. With this they wag away the sediment layer and thus expose the mussels. This observation was further corroborated by measurements on a good two dozen walrus skeletons from museum collections. In fact, in all of them the anterior limbs (scapula, humerus, ulna) were significantly longer on the right than on the left.
In addition to this preferred method of exposing their food, walruses also often use their left front fin, produce an extremely strong water jet with their mouths, or slide through the sediment on their snouts (with which one must again agree with the ancient Greeks: Odobenus, the tooth walker…).
And the tusks? The old opinion that walruses dig up their food with their powerful canines is wrong and has long been disproved. The teeth serve as weapons, have a social signaling function, are useful for hauling out onto an ice floe, enlarge a breathing hole in pack ice in an instant, or provide a handy “pillow” during sudden bouts of fatigue on land.
And there a walrus comes only to rest, because life outside the water is not at all fun for such a heavy, clumsy seal. Walrus resting places are then only found on shallow Arctic beaches, usually close to good feeding areas in shallow marine regions, and only a few dozen meters from the sea.
Long gestation and rearing
In summer, after a sumptuous shellfish meal, these powerful swimmers return almost white-skinned to a resting place where they are crowded together, dozens to thousands of them dozing peacefully in the Arctic sun. After only a short time, the thick layers of blubber and skin have a pleasant blood supply again, and the animals take on a pinkish color. In winter, however, walruses live south of their then icy summer haunts, far out to sea, at the edge of the pack ice.
Somewhere out there in the Arctic Ocean, during the gloomy twilight of the polar winter, the walruses are mating. It takes 15 to 16 months for the baby walrus to be born, after which it is nursed for a good two years – one reason why female walruses can only carry a calf one every 2 to 3 years. No other seal species has such a low reproduction rate.
And if you now look long enough into the small, short-sighted, red eyes of a walrus, think of its sad history and its fascinating life, then you will involuntarily take “this most monstrous of all seals” (Brehm’s “Thierleben”) into your heart.
Walrus Web Tip:
Currently, a film sequence in avi format can be downloaded from the Internet at www.biomedcentral.com/1472-6785/3/9, there in the chapter “Results” under point 3, which illustrates the peculiar search for food of a walrus on the seabed off East Greenland.
By Peter Balwin (Text)