The northern elephant seal is smaller in size than its southern counterpart. It lives along the Pacific coast of the US and Canada. The southern one is sighted along the coasts of South Africa, New Zealand, and Argentina. In fact, the Valdes Peninsula in Argentina is the fourth largest elephant seal colony in the world. It is so named because of the enormous size of its body and the proboscis that the adult bulls have. The large proboscis resembles an elephant's trunk, and even produces loud, roaring noises. The roaring sound is heard the most during the mating season. The proboscis, in the bull, is filled with cavities that enable the mammal to rebreathe and reabsorb the moisture lost while exhaling.
During the mating season, the male seal leaves the beach rarely, to feed or otherwise, and hence, it becomes very essential for the mammal to retain body moisture. The loud roaring noises generated by the bulls through the proboscis is not only to attract the cows, but also to generate the incoming source of the required moisture. They grow to a length of nearly 5.5 m, and weigh around 2,200 kg. The average lifespan or life expectancy of the female is about 20 years, while that of the bull is 14. The female matures and can give birth from the time period between 3 - 4 years, while the bulls reach maturity at five years. Even though the bulls mature at five years, they only achieve alpha status by the age of 8. In bull seals, the breeding years are between 9 and 12.
The bull is much larger than a cow. The cows or the females measure approximately 3 m in length, and weigh about 650 kg. The largest bull elephant seal on record weighed 5,000 kg, and was 6.9 m in length. They spend most of their lives in the ocean, and can hold their breath for over an hour. The highest record of 80 minutes makes them the record holders among the other non-cetacean mammals. In a single dive, they can cover a depth of nearly 1,500 meters! They are known to dive beneath the ocean's surface to search for prey like octopuses, eels, skates, rays, and even sharks.
Elephant seals are excellent swimmers and great runners on land too. They are known to reach a greater velocity than the average human. They have a lot of blubber under their skin that shields them from extreme cold. The blubber is more effective in keeping the cold at bay than the fur. They are susceptible to cold when the skin on top of the blubber and the fur molts. This is because regrowth requires the blood vessels to go through the blubber. At this time, it 'hauls out' or finds a safe resting place on land. The interesting point to note is that when they undergo the catastrophic molt, the bulls refrain from quarreling or fighting with one another.
They need a large amount of oxygen when diving deep to feed. This supply of oxygen is produced by the large volume of blood in their bodies. The large sinuses in their abdomens store oxygenated blood. They also have a larger proportion of red blood cells as compared to other mammals. These oxygen carriers aid the mammal's underwater escapades, that sometimes last for up to two hours. The anatomy of the elephant seal is designed to enable the mammal to survive harsh weather conditions and terrain. This amazing creature is affected by man-made influences of global warming and water pollution. It adds beauty to snow-covered regions, and it is up to us to ensure that their roars continue to resound through the crisp, chill air.