Hooded Seal (Cystophora cristata), a Weird Animal

The female Hooded Seal looks like a normal spotted seal, but the adult males are just plain weird.

This large marine mammal carries an inflatable beach ball attached to his head. This pouch is an enlargement of the nasal cavity and hangs down between his eyes and down over his upper lip when deflated.

To inflate his hood, the seal holds both nostrils shut and blows! When fully inflated, the hood is approximately twice the size of a football. As if this were not strange enough, he has the ability to blow a balloon from his nostrils.

He manages this by holding only one nostril closed – the air then inflates a membrane from the inside of his nose, which looks very much like a red balloon. (What do you think happens when he sneezes?)

The video of a hooded seal below shows a baby much too young to have grown the strange inflatable hood. But he’s absolutely adorable!

The obvious question, of course, is why would a seal need this inflatable bladder on top of his head, or a balloon to protrude from his nostril? They have been seen to inflate these structures when disturbed or during mating season, but Judith E. King states, in her book Seals of the World, that these animals are often seen lying calmly on drifting ice, blowing up their hoods and then deflating them in a way that looks as though they are just playing with them.

Of course the only time humans ever see these animals are when they are lying about on top of an ice floe. Most of their lives are spent in water, where the inflatable balloon may have some purpose known only to the seal. (Just for fun, can you think of any other animals that have features that seem silly or even unreasonable to us? Or perhaps write an essay on the possible uses of the Hooded Seal’s hood that we haven’t thought of yet.)

Even though the adult males are a bit odd looking, to say the least, their babies are born with coats that are so soft and beautiful that many are killed during the annual seal hunts off Labrador and Greenland. These pups are called “blue-backs” and are a beautiful silvery blue-gray on their backs, and creamy white on their bellies.

They are born on floating ice off the coast of Labrador and Greenland in the same area as the Harp Seal, another seal pup hunted for it’s coat. While the Harp Seal mother will usually abandon her pup when hunters approach, the female Hooded Seal is much more aggressive, and will stay to defend her baby. A large male is usually nearby, waiting to mate, and he will also defend the threatened pup.

Mating takes place when the pup is weaned, just 3 1/2 to 10 days after it is born, which is the shortest lactation period known among mammals. But during this very short time, the pup will double it’s body weight. The female does not become immediately pregnant after mating, because there is a 3 1/2 month delay in implantation of the egg. She will give birth again towards the end of March.

These seals are solitary animals except during the birthing/mating period when they are found in “families” of two adults and one pup, and again in July and August when they gather on ice floes during the molting season. Little is known about their migrations or lifestyle, since most information has so far come from the sealing industry, and most of the web sites that are concerned with the Hooded Seal concentrate on the inhumane hunting of pups and juveniles for their pelts.

(Just for fun, you might want to search for some of the web sites that discuss the sealing industry and the impact it has on the population of this weird, but wonderful, animal. To do that, just go to www.google.com and put “hooded seal” or harp seal” in the search box. You might want to have an adult with you when you look at these sites, because some of them are rather graphic, (pictures of dead and dying seals), and your parents or teacher may want to check them first).