Five Days With Fat Hoods - hooded seals grow up fast

International Wildlife, Jan, 1999

That is the essence of its young life, for the fatter the pup at weaning, the greater are its chances for a long and successful life. The fattest are the fittest for survival.

The female is less hostile today. When I approach to within 30 feet, half yesterday's distance, she growls a warning but does not attack. In addition to me, she has acquired a suitor. He is a minor male and hasn't got a chance. Until the female comes into estrus, she is hostile toward males and keeps them at a distance.

Top males know this and don't waste their time waiting and hoping. They cruise the ice searching for receptive females, drive off rivals of inferior rank, mate and move on in search of other conquests.

The large hooded seal males are powerful, impressive animals. Atop the male's forehead is a dull black skin sac, flaccid in repose, that the male can inflate into the two-humped crest or "hood" to which it owes both its common and scientific names: hooded seal, Cystophora cristata, the "bladder-carrying crested" seal.

As an encore to manipulating the hood to impress a rival or woo a female, the adult male can extrude the nasal septum from his left nostril and inflate it into a soccer-ball-sized, dull brown to orange red balloon. A tracery of blood vessels ornaments the thin, distended membrane. For maximum effect, the male usually holds his head high, blows up his nasal balloon, shakes his head vigorously from side to side and deflates the balloon with a squishy-gurgly sound.

For the moment, "my" female is not impressed. Her entire devotion is focused upon her pup, to protect it and feed it, to transfer to it from her blubber-swathed body via her rich milk a maximum of fat and energy. It shows. By nightfall, the pup is distinctly fatter than it was in the morning.

DAY 3: MOM'S DEVOTION WANES

The female is getting used to my daily low-key presence. When I arrive, walking slowly, she growls a bit, but it is only pro forma, to tell me I should not come too close to her precious pup.

She has a new suitor, a 500-pound mid-echelon male. He does not like me. He is long of tooth and short of temper and so sexually excited he may see in me a rival. As soon as I come close, he growls, a nasty, gargling basso profundo growl, and attacks. But all I have to do is step into the female's private sphere and she charges--not me but the pursuing male--and chases him away. She now, in a way, protects not only her pup but also me. She tolerates my presence at 15 feet but attacks any male seal that comes closer than 30 feet. Near her, I am quite safe.

Her pup is bulging. It has gained 30 pounds since its birth. The high-speed energy transfer from hooded seal mother to pup is amazingly efficient. As a general rule in many pinnipeds, the pup should attain at weaning about a fourth of its mother's weight to survive and prosper.

To achieve this, a northern elephant seal cow, for instance, needs about four weeks. In that time her pup, 80 pounds at birth, turns into a 300-pound "weaner," as weaned elephant seal pups are called. But the strain on the mother is visible: She arrives swathed in blubber, invests 56 percent of that in living ashore without food and in fattening her pup, and leaves gaunt and famished. By contrast, the hooded seal mother invests only 33 percent of her fat reserves to turn her slender birthling in four days into a furry blimp with flippers.