Walruses suck!

They really do! Let me explain.

I’d only seen walruses (Odobenus rosmarus, ‘odobenus’ from the Greek meaning ‘tooth-walker’; they sometimes haul themselves out of the water using their tusks) in TV documentaries, a la David Attenborough. I think Taronga Zoo in Sydney has at least one, but seeing such animals in the wild is a very, very different experience and much to be preferred if you can.

Walruses, like the polar bear, seem adorable, but this is a slightly condescending attitude we may have only if we are temporary visitors, far removed from the realities of living with them, unlike the Inuit who have relied on the North American population for food, knives and other tools, and weapons, for generations. Like with the Inuit, respect is paramount, along with the recognition that these are wild, and so potentially dangerous, animals. There are no native peoples in Svalbard, but walruses’ tough skin and ivory were sought after by Europeans there until protection in 1952. Numbers are increasing, from pretty much nothing to about 2,000 now.

Walrus haul-out, Svalbard

We saw the steam coming off the walruses before we saw the colony.

 

In the zodiac we sneaked up very quietly, turning off the engine and paddling the past few dozens of metres so as not to disturb them, and kept more than the minimum 30 m away. The guide asked us to speak in whispers if at all. Of course, the enormous beasts saw us and a few swam out to investigate, coming right up to the zodiacs in some cases.

They are very social and like to touch each other (thigmotactic).

Photo by Bruce Moore
Photo by Bruce Moore


Photo by Bruce Moore

The red colouration is due to the expansion of capillaries on the skin, helping the walrus lose heat.

The tusks can grow up to 1 m, but can get broken off in male-male breeding battles. Females have tusks, too.

Long walrus tusks in the Oslo Natural History Museum

According to National Geographic:

Walruses use their iconic long tusks for a variety of reasons, each of which makes their lives in the Arctic a bit easier. They use them to haul their enormous bodies out of frigid waters, thus their “tooth-walking” label, and to break breathing holes into ice from below. Their tusks, which are found on both males and females, can extend to about three feet, and are, in fact, large canine teeth, which grow throughout their lives. Male walruses, or bulls, also employ their tusks aggressively to maintain territory and, during mating season, to protect their harems of females, or cows.

Walruses apparently don’t see terribly well (it wouldn’t make sense to rely on eyesight in any season except summer, and don’t need it when feeding), but can smell – to detect the approach of predators (like polar bears) and identify their young – and hear extremely well (noises up to a mile or 1.6 km away). The whiskers (vibrissae, which can grow up to a foot or 30 cm long but mostly break off in contact with the sea bottom) are very sensitive. Walruses mostly eat clams buried in mud, but also take worms, crabs and sea cucumbers on the sea floor, diving down to 10-50 metres, and have been seen to eat ducks and seals!

Now the sucky bit. They rummage around on the sea floor, using their flippers and squirting water out to clear the clams of mud. Then they literally suck the soft parts right out of their shells, leaving the empty shells behind. A 2003 paper, ‘Feeding behaviour of free-ranging walruses with notes on apparent dextrality of flipper use’, goes into quite a bit of detail, concluding, among other things, that walruses are mainly, err, right-flippered.

Walruses mouths create massive suction. Photo by Bruce Moore

The paper says:

Walruses (Odobenus rosmarus) are highly specialised benthic feeders feeding almost exclusively on bivalves, making them an important component of the benthic ecosystem. It is mainly the soft parts of the bivalves that are found in walrus stomachs, with pieces of shells seen only rarely. Almost 6400 bivalve siphons have been reported in a single walrus stomach …

The walruses showed four different foraging behaviours; removing sediment by beating the right flipper, removing sediment by beating the left flipper, removing sediment by use of a water-jet from the mouth and rooting through sediment with the muzzle. There was a significant preference for using right flipper over left flipper during foraging.

I rather liked this 1962 nature journal detailing an expedition to one of the Svalbard fjords.

The whole skeleton gives you an idea of the size.



Walrus illustration, Longyearbyen Museum

It was yet another awesome encounter in Svalbard.

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This entry was posted in Animals on land, The sea, Travels and tagged , , . Bookmark the permalink.

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