Southern Elephant Seals: Characteristics, Behavior, Mating | Sea Life, Islands and Oceania

SOUTHERN ELEPHANT SEALS

Southern elephant seal males

Southern elephant seals (Scientific name: Mirounga leonina) are slightly larger, more numerous but less studied than northern elephant seals, the other elephant seal species. The range of these species do not overlap. Male southern elephant seals can live to be 14 years old while females can live to be 20 years old. On average, southern elephant seals live about 9.5 years. There are around 325,000 of them, [Source: Maelan Hauswirth, Animal Diversity Web (ADW) /=]

Southern elephant seals inhabit large portions of the southern hemisphere. This includes coastal areas and islands of Antarctica and islands south of and the southern tips of Africa, South America, Australia and New Zealand. When foraging for food, Southern elephant seals travel between 40º latitude south and the Antarctica mainland. Southern elephant seals inhabit a large portion of the southern hemisphere, but major breeding populations are only in a handful of places sub-Antarctic islands and in Antarctica. They are also found on the Valdes Peninsula in South America. They spend much of their time in the open seas of the Southern Ocean and the southern Pacific, Atlantic, and Indian oceans. They only come to land when they breed, moult, give birth, and take care of their offspring. When on land, they stay on beaches close to the ocean. Southern elephant seals are typically found in deep water at depths of 200 to 1000 meters (656 to 3280 feet). They feed in deep water and can dive up to 1,000 meters (3,300 feet) deep, even reaching the sea floor in areas. When sometimes rest on ice flows.

Feeding: Southern elephant seals are large ocean predators that feed mostly on squids, such as glacial squid and smooth hooked squid as well as various species of fish. They can dive to great depths to secure food and do not eat during the period when they give birth and mating, living off fat stores they build up the rest of the year. These fat stores also help them stay warm in the cold ocean. The main known predators of southern elephant seals are orcas (killer whales) and leopard seals. Southern elephant seals fight back with their teeth, or swim away when they encounter predator but mostly they dive deeper than their pursuers are capable of going. Southern elephant seals can sometimes become bycatch in fishing lines and be killed.

Websites and Resources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Fishbase fishbase.se; Encyclopedia of Life eol.org; Smithsonian Oceans Portal ocean.si.edu/ocean-life-ecosystems ; Monterey Bay Aquarium montereybayaquarium.org ; MarineBio marinebio.org/oceans/creatures

Southern Elephant Seal Physical Characteristics

Southern elephant seal range
Southern elephant seals range in length from 2.8 to six meters (9.2 to 19.7 feet), with their average length being 4.5 meters (14.8 feet). They range in weight from 400 to 3700 kilograms (880 to 8150 pounds). Sexual dimorphism (differences between males and females) is significant: Males are much larger than females. Males and females have different shapes and ornamentation. [Source: Maelan Hauswirth, Animal Diversity Web (ADW) /=]

Males have their distinctive proboscises on their faces. Older males usually have more scars on their necks from fighting with other males. Both males and females have short, brown fur, but when they molt, it exposes their grey skin. Southern elephant seals are endothermic (use their metabolism to generate heat and regulate body temperature independent of the temperatures around them), meaning they produce their own heat. Their torpedo-like shape and wide rear flippers make them strong swimmers.

Southern elephant seals are distinguished from northern elephant seals by their greater size and shorter proboscis. The southern males also appear taller when fighting, due to their tendency to bend their backs more strongly than the northern species. This species also exhibits the greatest sexual dimorphism of any mammal in terms of mass ratio, with males typically five to six times heavier than females. [Source: Wikipedia]

Southern Elephant Seal Behavior

Southern elephant seals are diurnal (active mainly during the daytime), motile (move around as opposed to being stationary), nomadic (move from place to place, generally within a well-defined range), migratory (make seasonal movements between regions, such as between breeding and wintering grounds), have daily torpor (a period of reduced activity, sometimes accompanied by a reduction in the metabolic rate, especially among animals with highmetabolic rates), territorial (defend an area within the home range), colonial (living together in groups or in close proximity to each other), and have dominance hierarchies (ranking systems or pecking orders among members of a long-term social group, where dominance status affects access to resources or mates). [Source: Maelan Hauswirth, Animal Diversity Web (ADW) /=]

elephant seal skeleton

The only time southern elephant seals gather in large numbers is when they come back on land to give birth, mate, and molt their fur. According to Animal Diversity Web: While on land, females give birth and nurse their pups for three weeks. During that time, older male bulls and mothers will guard the babies. Once pups have been nursing for three weeks, males start to form harems and fight over females, which can result in some babies being trampled. Older males fight for control over groups of females and this can include bloody fights, where males will run into one another and bite each other on the neck, leaving gashes and scars. When fighting, males will aim for the proboscis of their opponents and try to pin their opponents to the ground. Losers are forced to retreat. During the day, southern elephant seals may go into torpor to conserve energy.

Southern elephant seals communicate with vision and sound and sense using vision, touch, sound and chemicals usually detected with smell. During the mating season, male l challenge each other by using their proboscises to make a roaring sound. They show off their size. Opponents inspect each other and, if they decide to fight, will lunge at each other with their mouths open. Losers retreat and let out high pitched cries.

Southern Elephant Seal Mating and Reproduction

Southern elephant seals are viviparous, meaning they give birth to live young that developed in the body of the mother, and engage in seasonal breeding. Females have an estrous cycle, which is similar to the menstrual cycle of human females. They engage in delayed implantation (a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months). Elephant seals do not implant eggs until 4 months after mating and all of the pups are born about the same time seven months later. [Source: Maelan Hauswirth, Animal Diversity Web (ADW) /=]

Southern elephant seals breed once a year. Mating can occur at the end of September, but usually occurs mid-to-late October. The number of offspring is usually one but sometimes twins are born. The average gestation period is seven months. Females reach sexual maturity at three to six years. The average is four years. Males reach sexual maturity at five to eight years. The average is six years.

Southern elephant seals are generally polygynous (males having more than one female as a mate at one time) but are sometimes polygynandrous (promiscuous), with both males and females having multiple partners. Usually, a harem of less than 50 is controlled by one breeding bull.. If the harem has over 50 females, then more breeding males may control it. Breeding bulls protect their harem of females on the beach of their colony. After three to five weeks, mating begins. Older and more experienced males usually control the harems, but younger and less experienced bulls try to sneak into the harem territory and mate with females. /=\

Southern Elephant Parenting and Offspring

Southern elephant seal young are precocial. This means they are relatively well-developed when born. Parental care is provided by females. Pre-fertilization protection is provided by the male. During the pre-weaning stage provisioning and protecting is done by females. Pre-independence protection is provided by the male. The weaning age ranges from 18 to 27 days. The average weaning age is 22 days and the age in which young become independent ranges from six to seven weeks and the average time to independence is seven weeks. [Source: Maelan Hauswirth, Animal Diversity Web (ADW) /=]

Female pups weigh 24 to 50 kilograms (53 to 110 pounds) at birth and males weigh 27 to 53 kilograms (60 to 120 pounds) at birth. About six to seven weeks after they are born they are considered independent. /=\

Female southern elephant seals swim ashore before their pups are born. Once their pups are born, they feed them milk and protect them. After three to five weeks, females finish weaning their pups. Since it takes about a year to gestate, birth, and wean their pups, mating begins around the same time as weaning. After mating, females go into the ocean to feed and does not return to her pup. Small groups of weaned pups are guarded by bachelor seals, but offspring can sometimes be killed by other adult males. Once all of the adults leave the beach, the pups will eventually venture out to the ocean to look for food once they are hungry./=\

Southern Elephant Seals, Humans and Threats

They are not endangered. They are designated as a species of least concern on the International Union for Conservation of Nature (IUCN) Red List and have no special status on Trade in Endangered Species (CITES) places them in Appendix II, which lists species not necessarily threatened with extinction now but that may become so unless trade is closely controlled. /=\ According to the IUCN the current southern elephant seal population has a stable trend, is not severely fragmented, and has had no extreme fluctuations.

Southern elephant seals were hunted by indigenous people in Australia and South America for thousands of years. From the early 19th century until 1964, they were heavily harvested by commercial companies who primarily sought their blubber which they turned into oil. They were never hunted as extensively as northern elephant seals though

Nowadays, they are viewed by tourists when the animals come ashore to breed. Even so they are considered dangerous. They are very large animals that could potentially kill or harm a person if they come too close. There are photographs towering over cars and block roads. Southern elephant sometimes accidentally get caught up in fishing lines but they tend to hunt in places where fishing boats are not so prevalent.

Image Sources: Wikimedia Commons, NOAA

Text Sources: Animal Diversity Web (ADW) animaldiversity.org; National Oceanic and Atmospheric Administration (NOAA) noaa.gov; Wikipedia, National Geographic, Live Science, BBC, Smithsonian, New York Times, Washington Post, Los Angeles Times, The New Yorker, Reuters, Associated Press, Lonely Planet Guides and various books and other publications.

Last Updated June 2023