Elephant tusk

Article

May 21, 2022

The Elephant Grouse (Mirounga leonina) is a large marine mammal of the seal family, the largest pinniped and the largest representative of the order of the beast in the world. Together with the related Northern Grouse, it represents one of the two members of the Grouse genus. Elephant toads occur only in the southern hemisphere in areas close to Antarctica, such as the Southern Ocean and the southern Indian, Pacific and Atlantic Oceans. The total population is difficult to determine; the International Union for Conservation of Nature (IUCN) estimated it to have 325,000 adults living in four subpopulations by 2015. Like other seals, grouse have an elongated body of aerodynamic shape covered with a thick layer of subcutaneous fat. The limbs are finished with fins. The front fins have full-fledged claws, the hind ones have stunted claws. Mallards weigh 1.5-3 tons, exceptionally up to 5 tons. In contrast, females weigh only 400-600 kg, exceptionally up to 1 ton. In the extreme case, the male weighs up to 10 times more than the female, which is one of the largest size disparities between males and females of all mammals. For males, a typical skin sac (also called a trunk, hence the species name "elephant") at the end of the snout, which serves mainly to amplify the roar, which is important for defining the hierarchy. The breeding season begins in August to September, when males first arrive on land and start fighting for a hierarchical position. The Grouse practice extreme polygyny, and only the largest and strongest males eventually mate. The alpha male is usually older than 12 years. When the first females arrive at the colony, alpha males begin chasing them into groups called harems. Harems may have only a few females, but typically number several tens or hundreds of females. The largest recorded harems had over one thousand females. A few days after arriving on land, Rypoušice gives birth to young that are the result of the previous breeding season. The cub sucks milk for about 23 days. At the end of the lactation period, the female mates with the males and goes to sea. At the end of the breeding season (approximately November), males also go to sea, and the young stay on the shore for another 40-50 days. Adults come back to shore in a few weeks when they are molting, after which they go to sea again. The reptiles spend about 8-10 months a year at sea, and about 90% of their time is spent underwater, where they can last up to 2 hours. They typically dive to depths of 400-600m, but dives to depths of over 2 km have been recorded. They feed mainly on ten-armed natives and fish. In the 19th century, burrowing was widely hunted for its subcutaneous fat, which was used to make oil used in lamps and the textile industry. While most populations are stable or even rising slightly, the population of Macquarie Island has been steadily declining since the 1960s at the latest. The causes are not entirely clear, but they are usually related to the availability of food, respectively. environmental change. However, the total population of tusks is stable and currently not threatened by anything, so the IUCN considers the species to be little affected. In the future, however, the reptiles will affect global warming.

Scientific Systematics

Taxonomy and name

The first scientific description of the elephant seal was published by the Swedish naturalist Carl Linnaeus in 1758 in the 10th edition of his work Systema naturae. Linnaeus assigned the species the binomial name Phoca leonina (from the Latin terms phoca, which means seal, and leonina, or lion, literally "lion seal"). One of the first, if not the first, detailed descriptions of the biology of elephant seals comes from the French naturalist François Péron, who in 1802 visited King Island near the shores of Tasmania, where they had