What do you get if you cross a zebra with a seal? There is no sensible answer to that question, of course, but there is a species of seal which lives in the Arctic and subarctic regions of the North Pacific Ocean which could (however unfeasibly) be the product of a chance romance between the two species. It is the Ribbon Seal and it is remarkable for its stripes.
Like many seals, the ribbon seal (
Histriophoca fasciata) has dark brown to black fur. Yet what makes it standout is its remarkable and conspicuous coloration. It has two white stripes and two circles which pattern its body in a particularly striking way. Its genus –
Histriophoca – has a single member: you’re looking at it. The ribbon seal is one of a kind.
When they are born, ribbon seals are white – this is their natal fur and will moult as they grow. They are inconspicuous for four years, with grey fur on their backs and silver on their bellies. Then something remarkable happens. Some portions of their fur become much darker and other parts significantly brighter. This difference is more noticeable in the male. It is thought that the stripes indicate that the individual has reached sexual maturity and is ready to find a mate.
When the ribbon seal makes a leap for the water it makes for quite a remarkable sight. The distinctive markings, with two stripes, one around the head and the other around the tail plus the two circular strips on each side of its body gives the appearance of aerodynamic design.
The Pacific Ocean is the home of the ribbon seal but during the winter and spring it arrives at the ice packs of the Okhotsk and Bering seas to breed and give birth. Later in the year it will move even further north as the ocean warms. As it spends its time almost always at sea and in waters so far away from land there is not much known about its habits during these periods. There are attempts to find out more with scientists fitting seals with satellite tags to track their underwater adventures.
The ribbon seal is not particularly social. It does not gather in any type of herd (which was fortunate in Soviet era hunting days as it made it much more difficult to catch than the more gregarious if hapless harp seals. Motherhood doesn’t last long either, with the pups leaving their mothers after just four or five weeks.
Once in the ocean the ribbon seal is hardly at the top of the food chain. It must keep an eye out for orcas not to mention two species of shark, the Pacific sleeper and Arctic sleeper. On land it will make the occasional meal for a roving polar bear but the greatest threat to the species had, until recently, been us.
Although they are difficult to hunt due to their disinclination to live in groups, the ribbon seal pups were hunted for their fur. It looked as if their numbers might shrink to the verge of extinction but fortunately in 1969 the then Soviet Union put limits on the numbers that could be slaughtered.
Since the number of ribbon seals has bounced back with estimates of their current population standing at a relatively 250,000. It can only be hoped that this remarkable animal will be left to roam the Arctic oceans in peace.
First Image Credit NOAA Photo Library
