Elephant seals are large, oceangoing earless seals in the genus Mirounga. The two species, the northern elephant seal (M. angustirostris) and the southern elephant seal (M. leonina), were both hunted to the brink of extinction by the end of the 19th century, but the numbers have since recovered.
The northern elephant seal, somewhat smaller than its southern relative, ranges over the Pacific coast of the U.S., Canada and Mexico. The most northerly breeding location on the Pacific Coast is at Race Rocks, at the southern tip of Vancouver Island in the Strait of Juan de Fuca. The southern elephant seal is found in the Southern Hemisphere on islands such as South Georgia and Macquarie Island, and on the coasts of New Zealand, South Africa, and Argentina in the Peninsula Valdés. In southern Chile, there is a small colony of 120 animals at Jackson Bay, Admiralty Sound (Seno Almirantazgo), Tierra del Fuego. The oldest known unambiguous elephant seal fossils are fragmentary fossils of an unnamed member of the tribe Miroungini described from the late Pliocene Petane Formation of New Zealand. Teeth originally identified as representing an unnamed species of Mirounga have been found in South Africa, and dated to the Miocene epoch; however Boessenecker & Churchill (2016) considered these teeth to be almost certainly misidentified odontocete teeth.
Elephant seals breed annually and are seemingly faithful to colonies that have established breeding areas.
|Male and female northern elephant seals|
Elephant seals are marine mammals classified under the order Pinnipedia, which in Latin, means feather or fin footed. Elephant seals are considered true seals, and fall under the family Phocidae. Phocids (true seals) are characterized by having no external ear and reduced limbs. The reduction of their limbs helps them be more streamlined and move easily in the water. However, it makes navigating on land a bit difficult because they cannot turn their hind flippers forward to walk like the Otariids. In addition, the hind flipper of elephant seals have a lot of surface area, which helps propel them in the water. Elephant seals spend the majority of their time (90%) underwater in search of food, and can cover 60 miles a day when they head out to sea. When elephant seals are born, they can weigh up to 80 pounds and reach lengths up to 4 feet. Sexual dimorphism is prominently seen in elephant seals due to the fact that male elephant seals can weigh up to 10 times more than females. Also, the large proboscis, which is considered a secondary sexual characteristic, helps males assert dominance during mating season.
Elephant seals take their name from the large proboscis of the adult male (bull), which resembles an elephant's trunk. The bull's proboscis is used in producing extraordinarily loud roaring noises, especially during the mating season. More importantly, however, the nose acts as a sort of rebreather, filled with cavities designed to reabsorb moisture from their exhalations. This is important during the mating season when the seals do not leave the beach to feed, and must conserve body moisture as there is no incoming source of water. They are colossally large in comparison with other pinnipeds, with southern elephant seal bulls typically reaching a length of 5 m (16 ft) and a weight of 3,000 kg (6,600 lb), and are much larger than the adult females (cows), with some exceptionally large males reaching up to 6 m (20 ft) in length and weighing 4,000 kg (8,800 lb); cows typically measure about 3 m (10 ft) and 900 kg (2,000 lb). Northern elephant seal bulls reach a length of 4.3 to 4.8 m (14 to 16 ft) and the heaviest weigh about 2,500 kg (5,500 lb).
The northern and southern elephant seal can be distinguished by looking at various external features. On average, the southern elephant seal tends to be larger than the northern species. Adult male elephant seals belonging to the northern species tend to have a larger proboscis, and thick chest area with a red coloration compared to the southern species. Females do not have the large proboscis and can be distinguished between species by looking at their nose characteristics. Southern females tend to have a smaller, blunt nose compared to northern females.
|Image||Scientific name||Common Name||Distribution|
|M. angustirostris||Northern elephant seal||Eastern Pacific Ocean|
|M. leonina||Southern elephant seal||South Atlantic|
Elephant seals spend up to 80% of their lives in the ocean. They can hold their breath for more than 100 minutes – longer than any other noncetacean mammal. Elephant seals dive to 1,550 m (5,090 ft) beneath the ocean's surface (the deepest recorded dive of an elephant seal is 2,388 m (7,835 ft) by a southern elephant seal). The average depth of their dives is about 300 to 600 m (980 to 1,970 ft), typically for around 20 minutes for females and 60 minutes for males, as they search for their favorite foods, which are skates, rays, squid, octopuses, eels, small sharks and large fish. Their stomachs also often contain gastroliths. They spend only brief amounts of time at the surface to rest in between dives (2-3 minutes). Females tend to dive a bit deeper due to their prey source.
Elephant seals are shielded from extreme cold by their blubber, more so than by fur. Their hair and outer layers of skin molt in large patches. The skin has to be regrown by blood vessels reaching through the blubber. When molting occurs, the seal is susceptible to the cold, and must rest on land, in a safe place called a "haul out". Northern males and young adults haul out during June to July to molt; northern females and immature seals during April to May.
Elephant seals have a very large volume of blood, allowing them to hold a large amount of oxygen for use when diving. They have large sinuses in their abdomens to hold blood and can also store oxygen in their muscles with increased myoglobin concentrations in muscle. In addition, they have a larger proportion of oxygen-carrying red blood cells. These adaptations allow elephant seals to dive to such depths and remain underwater for up to two hours.
Elephant seals are also able to slow down their heartbeat (bradycardia) and divert blood flow from the external areas of the body to important core organs. In addition, they can also slow down their metabolism while performing deep dives.
Elephant seals also have a helpful feature in their bodies known as the countercurrent heat exchanger to help conserve energy and prevent heat loss. In this system, arteries and veins are organized in a way to maintain a constant body temperature by having the cool blood flowing to the heart warmed by blood going to external areas of the animal.
Milk produced by elephant seals is remarkably high in milkfat compared to other mammals. After an initially lower state, it rises to over 50% milkfat (human breast milk is about 4% milkfat, and cow milk is about 3.5% milkfat).
Elephant seals have large circular eyes that have more rods than cones to help them see in low light conditions when they are diving. These seals also possess a structure called the tapetum lucidum, which helps their vision by having light reflected back to the retina to allow more chances for photoreceptors to detect light.
Their body is covered in blubber, which helps them keep warm and reduce drag while they are swimming. The shape of their body also helps them maneuver well in the water, but limits their movement on land. Also, elephant seals have the ability to fast for long periods of time while breeding or molting. The turbinate process, another unique adaptation, is very beneficial when these seals are fasting, breeding, molting, or hauling out. This unique nasal structure recycles moisture when they breathe and helps prevent water loss.
Elephant seals have external whiskers called vibrissae to help them locate prey and navigate their environment. The vibrissae are connected to blood vessels, nerves, and muscles making them an important sensing tool.
Due to evolutionary changes, their ear has been modified to work extremely well underwater. The structure of the inner ear helps amplify incoming sounds, and allows these seals to have good directional hearing due to the isolation of the inner ear. In addition to these adaptations, tissues in the ear canal allow the pressure in the ear to be adjusted while these seals perform their deep dives.
Dominant males arrive at potential breeding sites in November, and will spend 3 months on the beach fasting to ensure that they can mate with as many females as possible. Male elephant seals use fighting, vocal noises, and different positions to determine who will be deemed the dominant male. When males reach 8 to 9 years of age, they have developed a pronounced long nose, in addition to a chest shield, which is thickened skin in their chest area. Showing off their noses, making loud vocalizations, and altering their posture are a few ways males show off their dominance. When battles come into play, seals will stand tall, and ram themselves into one another using their chest plates and sharp teeth.
When the pregnant females arrive, the dominating males have already selected their territory on the beach. Females cluster in groups called harems, which could consist up to 50 or more females surrounding one alpha male. Outside of these groups, a beta bull is normally roaming around on the beach. The beta bull helps the alpha by preventing other males accessing the females. In return, the beta bull might have an opportunity to mate with one of the females while the alpha is occupied.
Birth on average only takes a few minutes, and the mother and pup have a connection due to each other's unique smell and sound. The mothers will fast and nurse up to 28 days, providing their pups with rich milk. The last two to three days however, females will be ready to mate, and the dominant males will pounce on the opportunity. During this exhaustive process, males and females lose up to a third of their body weight during the breeding season. The gestation period for females is 11 months, and the pupping seasons lasts from mid December through the middle of February. The new pups will spend up to 10 more additional weeks on land learning how to swim and dive.
The average lifespan of a Northern Elephant Seal is 9 years, while the average lifespan of a Southern Elephant Seal is 20–22 years. Males reach maturity at five to six years, but generally do not achieve alpha status until the age of eight, with the prime breeding years being between ages 9 and 12. The longest life expectancy of a male northern elephant seal is approximately 14 years.
Females begin breeding at age 3–6 (median=4), and have one pup per breeding attempt. Once they begin breeding, 79% of adult females breed each year. Breeding success is much lower for first-time mothers relative to experienced breeders. Annual survival probability of adult females is 0.83 for experienced breeding females, but only 0.66 for first-time breeders indicating a significant cost of reproduction. More male pups are produced than female pups in years with warmer sea surface temperature in the northeastern Pacific Ocean.
Once a year, elephant seals go through a process called molting where they shed the outer layer of hair and skin. This molting process takes up to a month to fully complete. When it comes time to molt, they will haul out on land to shed their outer layer, and will not consume any food during this time. The females and juveniles will molt first, followed by the sub adult males, and finally the large mature males.
The IUCN lists both species of elephant seal as being of least concern, although they are still threatened by entanglement in marine debris, fishery interactions, and boat collisions. Though a complete population count of elephant seals is not possible because all age classes are not ashore at the same time, the most recent estimate of the California breeding stock was approximately 124,000 individuals. In the United States, the elephant seal, like all marine mammals, is protected under the Marine Mammal Protection Act (MMPA), passed in 1972, which outlaws hunting, killing, capture, and harassment of the animal.
Carnivora (; from Latin carō (stem carn-) "flesh" and vorāre "to devour") is a diverse scrotiferan order that includes over 280 species of placental mammals. Its members are formally referred to as carnivorans, whereas the word "carnivore" (often popularly applied to members of this group) can refer to any meat-eating organism. Carnivorans are the most diverse in size of any mammalian order, ranging from the least weasel (Mustela nivalis), at as little as 25 g (0.88 oz) and 11 cm (4.3 in), to the polar bear (Ursus maritimus), which can weigh up to 1,000 kg (2,200 lb), to the southern elephant seal (Mirounga leonina), whose adult males weigh up to 5,000 kg (11,000 lb) and measure up to 6.7 m (22 ft) in length.
Carnivorans have teeth and claws adapted for catching and eating other animals. Many hunt in packs and are social animals, giving them an advantage over larger prey. Some carnivorans, such as cats and pinnipeds, depend entirely on meat for their nutrition. Others, such as raccoons and bears, are more omnivorous, depending on the habitat. The giant panda is largely a herbivore, but also feeds on fish, eggs and insects. The polar bear subsists mainly on seals.
Carnivorans are split into two suborders: Feliformia ("catlike") and Caniformia ("doglike").Earless seal
The earless seals, phocids or true seals are one of the three main groups of mammals within the seal lineage, Pinnipedia. All true seals are members of the family Phocidae . They are sometimes called crawling seals to distinguish them from the fur seals and sea lions of the family Otariidae. Seals live in the oceans of both hemispheres and, with the exception of the more tropical monk seals, are mostly confined to polar, subpolar, and temperate climates. The Baikal seal is the only species of exclusively freshwater seal.East Antarctica
East Antarctica, also called Greater Antarctica, constitutes the majority (two-thirds) of the Antarctic continent, lying on the Indian Ocean side of the continent, separated from West Antarctica by the Transantarctic Mountains. It lies almost entirely within the Eastern Hemisphere and its name has been accepted for more than a century. It is generally higher than West Antarctica and includes the Gamburtsev Mountain Range in the centre.
Apart from small areas of the coast, East Antarctica is permanently covered by ice. The only terrestrial plant life is lichens, mosses and algae clinging to rocks, and there are a limited range of invertebrates including nematodes, springtails, mites and midges. The coasts are the breeding ground for various seabirds and penguins, and the leopard seal, Weddell seal, elephant seal, crabeater seal and Ross seal breed on the surrounding pack ice in summer.Elephant Point
Elephant Point is a small predominantly ice-free promontory projecting 2 km into Bransfield Strait at the south extremity of the west half of Livingston Island in the South Shetland Islands, Antarctica. The point forms the southwest side of the entrance to Kavarna Cove, and is surmounted by Rotch Dome on the north. Ice-free surface area 109 hectares (270 acres). The area was visited by early 19th century sealers.
The point is named after the Elephant seal species.Lake Moeraki
Lake Moeraki is a small lake on the Moeraki River on the West Coast of the South Island of New Zealand. State Highway 6 runs along its western edge.
The lake is surrounded by native vegetation and lies within the Te Wahipounamu World Heritage site.
Tours to watch Fiordland crested penguins are popular attractions for tourists. Since 1989, A bull southern elephant seal, named "Humphrey" returns annually . This species is rather rare on New Zealand coasts. Another individual sometimes migrate here as well. Occasionally, other pinnipeds such as New Zealand fur seals and sea lions visit around. Hector's dolphins may possibly swim along the shores.Leopard seal
The leopard seal (Hydrurga leptonyx), also referred to as the sea leopard, is the second largest species of seal in the Antarctic (after the southern elephant seal). Its only natural predators are the killer whale. It feeds on a wide range of prey including cephalopods, other pinnipeds, krill, birds and fish. It is the only species in the genus Hydrurga. Its closest relatives are the Ross seal, the crabeater seal and the Weddell seal, which together are known as the tribe of lobodontini seals. The name hydrurga means "water worker" and leptonyx is the Greek for "small clawed".M. leonina
M. leonina may refer to:
Macaca leonina, the northern pig-tailed macaque, a primate species
Melibe leonina, the hooded nudibranch or the lion nudibranch, a predatory sea slug species
Mirounga leonina, the southern elephant seal, an elephant seal speciesMinazo Vol. 1
Minazo Vol. 1 (美男象, Minazō) is an album by Japanese noise musician Merzbow. It was followed by Minazo Volume Two released on vinyl.
The album is dedicated to Minazo, who was the only male southern elephant seal in Japan. Minazo was brought from Uruguay in 1995, and was kept at Enoshima Aquarium until his death on October 4, 2005. He was 11 years old; the average life expectancy of an elephant seal is 20 years. In the liner notes, Masami Akita writes that Minazo was made to perform tricks at mealtime, which Akita speculates left him exhausted and may have led to his early death. Akita also laments that many of the aquariums in Japan are mere amusement establishments, and hopes that they will eventually end the exhibition of animals and only function as shelters.Minazo was depicted on the cover of Merzbeat.Minazo Volume Two
Minazo Volume Two is an album by the Japanese noise musician Merzbow. It is dedicated to Minazo, who was the only male southern elephant seal in Japan. It follows Minazo Vol. 1 released on CD.Naturama (Futurama)
"Naturama" is the thirteenth episode of the seventh season of the animated sitcom Futurama. It originally aired on Comedy Central on August 29, 2012.Northern elephant seal
The northern elephant seal (Mirounga angustirostris) is one of two species of elephant seal (the other is the southern elephant seal). It is a member of the family Phocidae (true seals). Elephant seals derive their name from their great size and from the male's large proboscis, which is used in making extraordinarily loud roaring noises, especially during the mating competition. Sexual dimorphism in size is great. Correspondingly, the mating system is highly polygynous; a successful male is able to impregnate up to 50 females in one season.Piedras Blancas Light Station
Piedras Blancas Light Station is located at Point Piedras Blancas, about 5.5 miles (8.9 km) west by northwest of San Simeon, California. It was added to the California Coastal National Monument in 2017.Pinniped
Pinnipeds, commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic marine mammals. They comprise the extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals). There are 33 extant species of pinnipeds, and more than 50 extinct species have been described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular evidence supports them as a monophyletic lineage (descended from one ancestral line). Pinnipeds belong to the order Carnivora and their closest living relatives are believed to be bears and the superfamily of musteloids (weasels, raccoons, skunks, and red pandas), having diverged about 50 million years ago.
Seals range in size from the 1 m (3 ft 3 in) and 45 kg (99 lb) Baikal seal to the 5 m (16 ft) and 3,200 kg (7,100 lb) southern elephant seal, which is also the largest member of the order Carnivora. Several species exhibit sexual dimorphism. They have streamlined bodies and four limbs that are modified into flippers. Though not as fast in the water as dolphins, seals are more flexible and agile. Otariids use their front limbs primarily to propel themselves through the water, while phocids and walruses use their hind limbs. Otariids and walruses have hind limbs that can be pulled under the body and used as legs on land. By comparison, terrestrial locomotion by phocids is more cumbersome. Otariids have visible external ears, while phocids and walruses lack these. Pinnipeds have well-developed senses—their eyesight and hearing are adapted for both air and water, and they have an advanced tactile system in their whiskers or vibrissae. Some species are well adapted for diving to great depths. They have a layer of fat, or blubber, under the skin to keep warm in the cold water, and, other than the walrus, all species are covered in fur.
Although pinnipeds are widespread, most species prefer the colder waters of the Northern and Southern Hemispheres. They spend most of their lives in the water, but come ashore to mate, give birth, molt or escape from predators, such as sharks and killer whales. They feed largely on fish and marine invertebrates; but a few, like the leopard seal, feed on large vertebrates, such as penguins and other seals. Walruses are specialized for feeding on bottom-dwelling mollusks. Male pinnipeds typically mate with more than one female (polygyny), although the degree of polygyny varies with the species. The males of land-breeding species tend to mate with a greater number of females than those of ice breeding species. Male pinniped strategies for reproductive success vary between defending females, defending territories that attract females and performing ritual displays or lek mating. Pups are typically born in the spring and summer months and females bear almost all the responsibility for raising them. Mothers of some species fast and nurse their young for a relatively short period of time while others take foraging trips at sea between nursing bouts. Walruses are known to nurse their young while at sea. Seals produce a number of vocalizations, notably the barks of California sea lions, the gong-like calls of walruses and the complex songs of Weddell seals.
The meat, blubber and fur coats of pinnipeds have traditionally been used by indigenous peoples of the Arctic. Seals have been depicted in various cultures worldwide. They are commonly kept in captivity and are even sometimes trained to perform tricks and tasks. Once relentlessly hunted by commercial industries for their products, seals and walruses are now protected by international law. The Japanese sea lion and the Caribbean monk seal have become extinct in the past century, while the Mediterranean monk seal and Hawaiian monk seal are ranked endangered by the International Union for Conservation of Nature. Besides hunting, pinnipeds also face threats from accidental trapping, marine pollution, and conflicts with local people.Proboscis
A proboscis is an elongated appendage from the head of an animal, either a vertebrate or an invertebrate. In invertebrates, the term usually refers to tubular mouthparts used for feeding and sucking. In vertebrates, a proboscis is an elongated nose or snout.San Simeon, California
San Simeon (ZIP Code: 93452; area code 805) is a town and census-designated place on the Pacific coast of San Luis Obispo County, California. Its position along State Route 1 is about halfway between Los Angeles and San Francisco, each of those cities being roughly 230 mi (370 km) away. A key feature of the area is Hearst Castle, a hilltop mansion built by William Randolph Hearst in the early 20th century that is now a tourist attraction. The area is also home to a large northern elephant seal rookery, known as the Piedras Blancas rookery. It is located 7 mi north of San Simeon on Highway 1.Seal Island (Shoalwater, Western Australia)
Seal Island (32°17′36″S 115°41′19″E) is located near Shoalwater, Western Australia in the Perth region. In December 2016, a rare birth of a southern elephant seal pup on the island was just the third such event recorded in Western Australia in 20 years and only the tenth in Australia since 1958.Southern elephant seal
The southern elephant seal (Mirounga leonina) is one of the two species of elephant seals. It is the largest member of the clade Pinnipedia and the order Carnivora, as well as the largest extant marine mammal that is not a cetacean. It gets its name from its massive size and the large proboscis of the adult male, which is used to produce very loud roars, especially during the breeding season. A bull southern elephant seal is about 40% heavier than a male northern elephant seal (Mirounga angustirostris), more than twice as heavy as a male walrus (Odobenus rosmarus), and six to seven times heavier than the largest living terrestrial carnivorans, the polar bear (Ursus maritimus) and the Kodiak bear (Ursus arctos middendorffi).Tagging of Pacific Predators
Tagging of Pacific Predators (TOPP) began in 2000 as one of many projects formed by Census of Marine Life, an organization whose goal is to help understand and explain the diversity and abundances of the ocean in the past, present, and future. After they were formed, TOPP began by building a coalition of researchers from all over the world to find and study predators of the Pacific Ocean. Since then, they have satellite-tagged 22 different species and more than 2,000 animals. These animals include elephant seals, great white sharks, leatherback turtles, squid, albatrosses, and more.Through the efforts of TOPP, information never before accessed by humans was now available, such as migration routes and ecosystems, but from the animals', rather than human, aspects. It also became possible to learn about the ocean itself through use of the animals, because they can go where humans cannot. We learn through their everyday actions, and through these data, researchers have been able to determine better ways of protecting endangered species, such as the leatherback turtle.
Extant Carnivora species