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March/April 2002 issue	In this issue Table of Contents Editor’s Notebook Inside Story Feature: Walrus À la carte Mosaic Reverberations

Grace under water | Walrus facts | Walrus anatomy
The walrus and the zookeeper | Archives

Through cunning words and trickery, the Walrus lures and prepares to eat the congregating horde of oysters in Lewis Carroll’s poem, The Walrus and the Carpenter. But the quantity of oysters this marine carnivore could eat far outweighs Carroll’s audience of a dozen-plus molluscs. "A walrus can eat up to 60 pounds (27 kilograms) a day, depending on the time of year," says Paul Sieswerda, curator for the New York Aquarium (NYA), which houses four walruses (Odobenus rosmarus).

Aquariums and zoos in North America have played an important part in the lives of the walrus, and the NYA is no exception. Hunting walrus was outlawed in Canada in 1930, followed by the U.S. and Russia, and it is now legal only for First Nations groups as a means of subsistence. Yet even minimal hunting can leave some calves orphaned, sentencing them to certain death. But zoos across the continent have come to the rescue. Expeditions of zoo staff have tagged along on subsistence hunts to save the forgotten animals.

One of the orphans rescued by the NYA, Nuka, Inuktitut for "little sister," is a 16-year-old female who, at more than 450 kilograms, is the biggest walrus at the aquarium. Maintaining such large marine mammals in an aquarium can be a challenge, but zoos and aquariums do have guidelines to follow. "The requirements for water space and dry resting area are set by our USDA (U.S. Department of Agriculture) and all aquariums must meet these minimum standards," says Sieswerda. "Walruses will eat most fish and shellfish. We feed them a variety, consisting of primarily herring and capelin. Some squid is also part of their daily diet."

The largest of the fin-footed mammals, a walrus bull can measure around 4 metres long and can weigh up to 1,400 kilograms, with females weighing about a third less than the males. Their tusks alone can weigh more than 4.5 kilograms each and can reach up to 90 centimetres in length, though they are usually about half as long. Their scientific family name is Odobenidae, Latin for "those that walk with teeth" — a fitting description for a marine mammal that uses its huge ivory tusks to haul itself onto an ice floe.

Regrettably, in captivity the characteristically mighty teeth of the walrus meet a rather ignoble end. "It is unfortunate that most walrus wear down their tusks in aquariums," says Sieswerda. "We have removed the tusks to prevent infection or continual wear." But the loss of dentition does nothing to hinder their social development in zoos, as it would in the wild since walrus males use their tusks in courtship and social standing. "We provide behavioural enrichment toys and interactions, which the walrus seem to enjoy," says Sieswerda. "We have one male and three females so the social activity can be exciting."

In the wild, walruses live in huge herds, alternating between lazily sunning themselves on beaches and ice floes and gracefully gliding along the ocean floor, relying mainly on touch to find food. Because of their tendency for social interaction and constant stimulation, zoo staff work closely with the walrus, an arrangement that benefits both humans and their fin-footed friends.

Another social behaviour among walrus is the formation of female harems, over which the bulls battle fiercely. During breeding season in February and March, social activity among the walruses is heightened. This is exactly what Sieswerda and others are hoping for with their tiny herd. "Walruses will breed in aquariums and zoos," says Sieswerda, who expects breeding activity to produce offspring soon. "Our male is eight years old and is sexually active with the females now." He adds the NYA will work with other institutions to maximize breeding in aquariums and to maintain a continuous population of animals for exhibits and research projects.

For the walrus, having a full social life also means verbal communication. Not the poetry spouted by the Carpenter’s friend in Carroll’s tale, but vocalization nonetheless. The males have inflatable air sacs on either side of their necks, allowing them to produce loud, resonant sounds that can be heard both above and below water. "These are very interesting and popular animals," says Sieswerda.

One can easily imagine a bull posturing on a sunny ledge one March afternoon in New York, heaving his mighty girth upright and bellowing to his female companions. What would his words be, if we could understand? Perhaps, they might be, "I am the Walrus; goo goo ga joob."

Tobi McIntyre

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