Geographic Range
Southern elephant seals (
Mirounga leonina
) inhabit large portions of the southern hemisphere. This includes lands in Antarctica
and islands in the southern part of Africa, South America, and Australia. When foraging
for food, Southern elephant seals travel between 40 degrees latitude south and the
continent of Antarctica. They spend their time in the Pacific, Atlantic, and Indian
oceans. They only come to land when they breed, give birth, and take care of their
offspring.
- Biogeographic Regions
- ethiopian
- neotropical
- australian
- antarctica
- oceanic islands
- indian ocean
- atlantic ocean
- pacific ocean
Habitat
Southern elephant seals live on land only when molting, breeding, and giving birth.
When on land, they stay on beaches close to the ocean. They feed in the Pacific, Atlantic,
and Indian oceans and can dive up to 1,000 m deep, even reaching the sea floor in
areas. When they rest out in the ocean it is on ice.
- Habitat Regions
- polar
- terrestrial
- saltwater or marine
- Terrestrial Biomes
- icecap
Physical Description
In Southern elephant seals, males are bigger than females and grow the signature proboscis
on their faces. Older males will usually have more scars on their necks from fighting
with other males. Males can grow up to 6 m long and weigh more than 3,700 kg. Females
can grow up to just above 2 m long. Both males and females have short, brown fur,
but when they molt, it exposes their grey skin. Southern elephant seals are endothermic,
meaning they produce their own heat. Their torpedo-like shape and wide rear flippers
make them strong swimmers.
- Other Physical Features
- endothermic
- bilateral symmetry
- Sexual Dimorphism
- male larger
- sexes shaped differently
- ornamentation
Reproduction
Southern elephant seals form harems of females, which are controlled by one breeding
bull if the harem has less than 50 females. As harem size increases to over 50 females,
more breeding males control the harem. Breeding bulls protect their harem of females
and after 3 to 5 weeks, mating begins. Older and more experienced males usually control
harems, but other younger and less experienced bulls may try to intrude and mate with
females.
- Mating System
- polygynous
- polygynandrous (promiscuous)
Southern elephant seals breed once a year. This can occur at the end of September,
but usually occurs from mid-to-late October. This time period is when females are
in estrus and are most fertile. Females usually give birth to one pup, but on rare
occasions they have twins. Elephant seals do not implant eggs until 4 months after
mating and all of the pups are born about the same time 7 months later. Female pups
weigh 24 to 50 kg at birth and males weigh 27 to 53 pounds at birth. Once pups are
born, it takes an average of 22 days for them to become weaned. About 6 to 7 weeks
after they are born they are considered independent. Female southern elephant seals
reach reproductive maturity between 3 and 6 years old and males reach maturity between
5 and 8 years old.
- Key Reproductive Features
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- viviparous
- delayed implantation
- post-partum estrous
Female southern elephant seals swim ashore before their pups are born. Once their
pups are born, they feed them milk and protect them. After 3 to 5 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.
- Parental Investment
- precocial
- female parental care
-
pre-fertilization
-
protecting
- male
-
protecting
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-independence
-
protecting
- male
-
protecting
Lifespan/Longevity
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.
Behavior
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. While on land, females give birth
and nurse their pups for 3 weeks. During that time, older male bulls and mothers will
guard the babies. Once pups have been nursing for 3 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.
- Key Behaviors
- terricolous
- natatorial
- diurnal
- motile
- nomadic
- migratory
- daily torpor
- territorial
- colonial
- dominance hierarchies
Home Range
Southern elephant seals inhabit a large portion of the southern hemisphere, but major
breeding populations are located on sub-Antarctic islands and in Antarctica. They
are also found on the Valdes Peninsula in South America.
Communication and Perception
Male southern elephant seals will challenge each other by using their proboscises
to make a roaring sound. They will also raise up on their hind fins to 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.
Food Habits
Southern elephant seals are carnivores who mostly eat squids, such as glacial squid
(
Psychroteuthis glacialis
) and smooth hooked squid (
Filippovia knipovitchi
), as well as various species of fish. Southern elephant seals are able to dive to
great depths in the ocean in order to find food. They do not eat during the period
when they give birth and mate, so they eat and build up fat stores throughout the
rest of the year. These fat stores help them stay warm in the cold ocean water.
- Primary Diet
- carnivore
- Animal Foods
- fish
- mollusks
Predation
Southern elephant seals can sometimes become bycatch in fishing lines and be killed.
Their main predators are orcas (
Orcinus orca
), some big sharks, and leopard seals (
Hydrurga leptonyx
). Southern elephant seals fight back with their teeth, or swim away when they encounter
predator.
Ecosystem Roles
Southern elephant seals are large predators in the ocean and feed on other fish and
squid. However, this causes a minimal impact on the populations of these species.
- None
- None
- None
Economic Importance for Humans: Positive
Southern elephant seals were hunted by indigenous people in Australia and South America
for thousands of years, but from the early 19th century until 1964, they were heavily
harvested by commercial companies wanting to turn their blubber into oil. Nowadays,
people pay to see them when they are beached and sleeping in the sand.
- Positive Impacts
- body parts are source of valuable material
- ecotourism
- research and education
Economic Importance for Humans: Negative
Southern elephant seals are large animals, and could potentially kill or harm a person
if they were to come too close. Also, deep sea fisheries can have their fishing equipment
damaged when southern elephant seals accidentally get caught up in fishing lines.
Conservation Status
According to the IUCN Redlist, southern elephant seals are listed as least concern
because their current population has a stable trend, is not severely fragmented, and
has had no extreme fluctuations. The southern elephant seal is listed under Appendix
II of CITES.
Additional Links
Contributors
Maelan Hauswirth (author), Colorado State University, Brooke Berger (editor), Colorado State University, Galen Burrell (editor), Special Projects.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Neotropical
-
living in the southern part of the New World. In other words, Central and South America.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Australian
-
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Antarctica
-
lives on Antarctica, the southernmost continent which sits astride the southern pole.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- oceanic islands
-
islands that are not part of continental shelf areas, they are not, and have never been, connected to a continental land mass, most typically these are volcanic islands.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Atlantic Ocean
-
the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- Pacific Ocean
-
body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- polar
-
the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.
- terrestrial
-
Living on the ground.
- saltwater or marine
-
mainly lives in oceans, seas, or other bodies of salt water.
- pelagic
-
An aquatic biome consisting of the open ocean, far from land, does not include sea bottom (benthic zone).
- benthic
-
Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.
- coastal
-
the nearshore aquatic habitats near a coast, or shoreline.
- sexual ornamentation
-
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
- polygynous
-
having more than one female as a mate at one time
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- delayed implantation
-
in mammals, a condition in which a fertilized egg reaches the uterus but delays its implantation in the uterine lining, sometimes for several months.
- young precocial
-
young are relatively well-developed when born
- female parental care
-
parental care is carried out by females
- natatorial
-
specialized for swimming
- diurnal
-
- active during the day, 2. lasting for one day.
- motile
-
having the capacity to move from one place to another.
- nomadic
-
generally wanders from place to place, usually within a well-defined range.
- migratory
-
makes seasonal movements between breeding and wintering grounds
- territorial
-
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- colonial
-
used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.
- dominance hierarchies
-
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
- ecotourism
-
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
- carnivore
-
an animal that mainly eats meat
- piscivore
-
an animal that mainly eats fish
- molluscivore
-
eats mollusks, members of Phylum Mollusca
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
References
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Anderson, G. 2003. "Elephant Seal Reproduction" (On-line). Marine Science. Accessed March 03, 2020 at http://marinebio.net/marinescience/05nekton/esrepro.htm .
California Department of Parks and Recreation, 2020. "Elephant Seals" (On-line). California Department of Parks and Recreation. Accessed March 03, 2020 at https://www.parks.ca.gov/?page_id=1115 .
Carrick, R., S. Csordas, S. Ingham. 1962. "Studies on the Southern Elephant Seal, mirounga leoniata" (On-line pdf). Accessed March 03, 2020 at https://www.publish.csiro.au/wr/pdf/CWR9620161 .
Convention on International Trade in Endangered Species, 2019. "Appendices" (On-line). Convention on International Trade in Endangered Species of Wild Fauna and Flora. Accessed March 09, 2020 at https://www.cites.org/eng/app/appendices.php .
Hoff, J., R. Kilpatrick, D. Welsford. 2017. Southern elephant seals (Mirounga leonina Linn.) depredate toothfish longlines in the midnight zone. PLoS ONE , 12/2: 1-13. Accessed March 10, 2020 at https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0172396 .
Hofmeyr, G. 2015. "Southern Elephant Seal" (On-line). IUCN Redlist. Accessed March 03, 2020 at https://www.iucnredlist.org/species/13583/45227247 .
Oceana, 2019. "Southern Elephant Seal" (On-line). Oceana. Accessed March 10, 2020 at https://oceana.org/marine-life/marine-mammals/southern-elephant-seal .
Reisinger, R., P. Bruyn, C. Tosh, W. Oosthuizen, N. Mufanadzo, M. Bester. 2011. Prey and seasonal abundance of killer whales at sub-Antarctic Marion Island. African Journal of Marine Science , Volume 33/ Issue 1: 99-105. Accessed March 10, 2020 at https://www.tandfonline.com/doi/abs/10.2989/1814232x.2011.572356 .
Rodhouse, P., T. Arnbom, M. Fedak, J. Yeatman, W. Murray. 1992. "Cephalopod Prey of the Southern Elephant Seal, Mirounga leonina L." (On-line pdf). Accessed March 03, 2020 at https://www.nrcresearchpress.com/doi/pdf/10.1139/z92-143 .