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Overview

Distribution

Range Description

Leopard Seals are widely distributed in Antarctic and sub-Antarctic waters of the Southern Hemisphere, occurring from the coast of the Antarctic continent northward throughout the pack ice and at most sub-Antarctic islands. There is a seasonal presence of juveniles at Kerguelen and Macquarie Islands with the greatest numbers being sighted in September and October (Rounseveld and Eberhard 1980,Borsa 1990). Vagrants regularly reach warm temperate latitudes.Leopard Sealshaul out on ice and on land, often preferring ice floes near shore when they are available (Kooyman 1981).
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Leopard seals (Hydrurga leptonyx) are predominately found in the circumpolar region of the Antarctic pack ice. Although small numbers can be found just beyond the pack ice on the nearby subantarctic islands year-round, there is greater dispersal into this area during the winter months.

Biogeographic Regions: antarctica (Native ); indian ocean (Native ); atlantic ocean (Native ); pacific ocean (Native )

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Physical Description

Morphology

Leopard seals are by far the largest of the antarctic seals. Males can grow up to 3 meters in length and weigh approximately 300 kg. Females are even larger, growing up to 3.8 meters in length and 500 kg. The overall body shape of leopard seals are long and slender, making it very agile in the water. Their coloring varies dorsally to ventrally with a dark grey back, a silvery grey underside, and dark and light spots throughout the entire body. The snout of leopard seals are long on their large head; well-designed for catching and handling prey.

Range mass: 300 to 500 kg.

Range length: 3 to 3.8 m.

Sexual Dimorphism: female larger

Other Physical Features: endothermic ; bilateral symmetry

  • Ray, C. 1970. Population Ecology of Antarctic Seals. Pp. 398-414 in M Holdgate, ed. Antarctic Ecology, Vol. 1. London, New York: Academic Press.
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Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
Adult male Leopard Seals are 2.8 to 3.3 m long and weigh up to 300 kg. Adult females are 2.9 to 3.6 m, with very large animals possibly reaching 3.8 m, and weights of 260 to upwards of 500 kg. Pups are 1.0 to 1.6 m in length and weigh 30 to 35 kg at birth. The age at sexual maturity is probably four years for females and 4.5 years for males. Longevity is estimated to be over 26 years (Kooyman 1981, Rogers 2009).

At sea and on the ice, Leopard Seals tend to be solitary. Pups are born on sea ice from early November to late December and the period may be as long as early October to early January (Southwell et al. 2003). Births at South Georgia occur from late August to the middle of September. Pups are probably weaned at four weeks old, and female oestrous occurs at or shortly after weaning. Unlike Crabeater Seals, male Leopard Seals do not haul out with female-pup pairs. Mating is believed to occur in the water, but has never been observed.

Leopard Seals are well known for preying upon penguins. However, their diet is in reality highly varied and changes with seasonal and local abundance of prey. Leopard Seals will consume krill, fish, squid, penguins, a variety of other types of seabirds, and juvenile seals including Crabeater, Southern Elephant and Fur Seals (Rogers 2009, Southwell et al. 2012). In the case of Antarctic Fur Seals, it has been proposed that predation of Leopard Seals on pups might have a significant role in driving population dynamics of the prey species in certain areas (Schwarz et al. 2013). Most prey are caught in the water. Penguins are usually held in the Leopard Seal's teeth by one end and slung in an arc with a rapid snap of the head and neck and smashed on the surface of the water until they are torn open. Smaller pieces are then swallowed. Young, newly fledged nave penguins are most vulnerable, but adult birds are taken as well. Leopard Seals patrol and regularly station themselves just off Penguin colonies and wait to ambush and chase animals transiting to and from the colonies (Rogers and Bryden 1995). Krill may be a seasonally important prey (Lowry et al. 1988).

There have been few studies of Leopard Seal diving. Two seals tagged with satellite-linked dive recordersdovemostly to 10-50 m, and the deepest dive recorded was 304 m (Nordy and Blix 2009).

Systems
  • Terrestrial
  • Marine
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Depth range based on 607 specimens in 1 taxon.
Water temperature and chemistry ranges based on 603 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): -1.670 - 1.883
  Nitrate (umol/L): 22.624 - 30.357
  Salinity (PPS): 33.643 - 33.980
  Oxygen (ml/l): 7.524 - 8.209
  Phosphate (umol/l): 1.246 - 2.058
  Silicate (umol/l): 19.880 - 66.028

Graphical representation

Temperature range (°C): -1.670 - 1.883

Nitrate (umol/L): 22.624 - 30.357

Salinity (PPS): 33.643 - 33.980

Oxygen (ml/l): 7.524 - 8.209

Phosphate (umol/l): 1.246 - 2.058

Silicate (umol/l): 19.880 - 66.028
 
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Leopard seals reside mostly on and around the pack ice of Antarctica, but may also be seen on the subantarctic islands if there is enough ice substrate. These seals are much more agile in the water than on ice, and water is where they spend much of their time. Leopard seals feed on species that reside in the surface waters of the ocean, and thus are found primarily in these waters.

Habitat Regions: polar ; saltwater or marine

Terrestrial Biomes: icecap

  • Jessopp, M., J. Reid, P. Trathan, E. Murphy. 2004. Winter dispersal of leopard seals (Hydrurga leptonyx): environmental factors influencing demographics and seasonal abundance. Journal of Zoology, 263: 251-258.
  • Laws, R. 1984. Antarctic Ecology Vol. II. London: Academic Press.
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Depth range based on 607 specimens in 1 taxon.
Water temperature and chemistry ranges based on 603 samples.

Environmental ranges
  Depth range (m): 0 - 0
  Temperature range (°C): -1.670 - 1.883
  Nitrate (umol/L): 22.624 - 30.357
  Salinity (PPS): 33.643 - 33.980
  Oxygen (ml/l): 7.524 - 8.209
  Phosphate (umol/l): 1.246 - 2.058
  Silicate (umol/l): 19.880 - 66.028

Graphical representation

Temperature range (°C): -1.670 - 1.883

Nitrate (umol/L): 22.624 - 30.357

Salinity (PPS): 33.643 - 33.980

Oxygen (ml/l): 7.524 - 8.209

Phosphate (umol/l): 1.246 - 2.058

Silicate (umol/l): 19.880 - 66.028
 
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Trophic Strategy

Leopard seals feed primarily on krill, using their lobodont teeth to filter these small crustaceans from the water. Although krill are their primary food source, leopard seals are also aggressive apex predators eating penguins, young crabeater seals, and squid.

Animal Foods: birds; mammals; fish; mollusks; aquatic crustaceans

Foraging Behavior: filter-feeding

Primary Diet: carnivore (Eats terrestrial vertebrates, Eats non-insect arthropods, Molluscivore )

  • Berkman, P. 2001. Science into Policy : Global Lessons from Antarctica. Burlington, MA: Academic Press.
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Associations

As apex predators, leopard seals play an important ecological role feeding on large animals that inhabit the extreme antarctic system.

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Leopard seals are apex predators, indicating that they are at the top of the Antarctic food chain. Their only known natural predators are killer whales, however leopard seals are rarely eaten.

Known Predators:

  • Killer Whales (Orcinus orca)

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Known predators

Hydrurga leptonyx (leopard seal) is prey of:
Odontoceti

Based on studies in:
Antarctic (Marine)

This list may not be complete but is based on published studies.
  • N. A. Mackintosh, A survey of antarctic biology up to 1945. In: Biologie antarctique, R. Carrick, M. Holdgate, J. Prevost, Eds. (Hermann, Paris, 1964), pp. 3-38.
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Known prey organisms

Hydrurga leptonyx (leopard seal) preys on:
Euphausia superba
Euphausia crystallorophias
Spheniscidae
Procellariidae
Actinopterygii
Aves
Cephalopoda

Based on studies in:
Antarctic (Estuarine)

This list may not be complete but is based on published studies.
  • G. A. Knox, Antarctic marine ecosystems. In: Antarctic Ecology, M. W. Holdgate, Ed. (Academic Press, New York, 1970) 1:69-96, from p. 87.
  • N. A. Mackintosh, A survey of antarctic biology up to 1945. In: Biologie antarctique, R. Carrick, M. Holdgate, J. Prevost, Eds. (Hermann, Paris, 1964), pp. 3-38.
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Life History and Behavior

Behavior

Not much is known regarding communication among leopard seals. However, males are known to vocalize just prior to and during the mating season. It is suspected that these sounds are used for mate attraction.

Communication Channels: acoustic

Perception Channels: tactile ; acoustic ; chemical

  • Opzeeland, I., S. Parijs, H. Bornemann, S. Frickenhaus, L. Kindermann, H. Klinck, J. Plotz, O. Boebel. 2010. Acoustic ecology of Antarctic pinnipeds. Marine Ecology Progress Series, 414: 267-291.
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Life Expectancy

There are few accounts of the lifespan of leopard seals. However, they have been recorded to live for up to 30 years in the wild, but the lifespan is speculated to be closer to 26 years.

Range lifespan

Status: wild:
30 (high) years.

Average lifespan

Status: wild:
26 years.

Average lifespan

Status: wild:
26.0 years.

Average lifespan

Sex: male

Status: wild:
23.0 years.

Average lifespan

Sex: female

Status: wild:
26.0 years.

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Lifespan, longevity, and ageing

Observations: The 2 months delayed implantation increases the pregnancy period to 11 months (Ronald Nowak 2003). In the wild, females have been estimated to live for more than 26 years (Bernhard Grzimek 1990). Little is known about their longevity in captivity. One wild born animal was about 17.3 years when it died in captivity (Richard Weigl 2005). Further studies are needed.
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Reproduction

Little is known about leopard seal mating systems, because they inhabit an extreme environment making direct observation difficult. Much of what is known was observed from captive individuals. Little is known about mate acquisition in leopard seals, but vocalization is thought to play a role as males become highly vocal during the breeding season. Mating occurs in the water in captive environments and wild populations are thought to behave similarly. After mating the female is left alone to wean the pups on the ice.

Mating System: polygynous

Birth of leopard seal pups generally occurs between late October and November, with newborn pups measuring on average 120 cm in length. For the next 4 weeks, the mother nurses her pups on an ice flow. Mating occurs during December and into the beginning of January shortly after the pups are weaned.

Breeding interval: Leopard seals breed once yearly.

Breeding season: The breeding lasts from December to early January.

Range number of offspring: 1 (high) .

Average number of offspring: 1.

Range weaning age: 4 (high) weeks.

Average age at sexual or reproductive maturity (female): 4 years.

Average age at sexual or reproductive maturity (male): 4.5 years.

Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous

Average birth mass: 30000 g.

Average gestation period: 274 days.

Average number of offspring: 1.

Average age at sexual or reproductive maturity (male)

Sex: male:
1461 days.

Average age at sexual or reproductive maturity (female)

Sex: female:
1095 days.

Leopard seals live a solitary life with the exception of a brief mating period, so there is little information describing mating interactions of males and females. It is, however, known that males do not provide any post-fertilization parental investment once they have mated with a female.

Female leopard seals are solely responsible for their pup once it is born. On the ice floes of Antarctica mother seals are seen nursing and protecting their young for approximately 4 weeks following birth. After these 4 weeks, the pup is weaned and shortly after females begin mating again. After the weaning period, there is not much known about leopard seal development. Juvenile leopard seals have, however, been observed in relatively large numbers on the nearby subantarctic islands.

Parental Investment: female parental care ; pre-fertilization (Provisioning); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)

  • Jefferson, T., S. Leatherwood, M. Webber. 1993. Marine Mammals of the World. Roome: United Nations Environment Programme, Food and Agriculture Organization of the United Nations.
  • Oritsland, T. 1970. Biology and Population Dynamics of Antarctic Seals. Pp. 361-366 in M Holdgate, ed. Antarctic Ecology, Vol. I. London: Academic Press.
  • Rogers, T. 2009. "Leopard seal (H. leptonyx)" (On-line). The Society for Marine Mammalogy. Accessed March 11, 2012 at http://www.marinemammalscience.org/index.php?option=com_content&view=article&id=459&Itemid=298.
  • Siniff, D. 1991. An Overview of the Ecology of Antarctic Seals. American Zoologist, 31: 143-149.
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Molecular Biology and Genetics

Molecular Biology

Barcode data: Hydrurga leptonyx

The following is a representative barcode sequence, the centroid of all available sequences for this species.


There are 4 barcode sequences available from BOLD and GenBank.

Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.

See the BOLD taxonomy browser for more complete information about this specimen and other sequences.

AACCGATGACTATTTTCCACAAACCATAAAGATATTGGTACCCTCTACTTATTATTTGGTGCATGAGCCGGAATAGTAGGAACTGCCCTCAGCCTTTTAATCCGCGCAGAACTAGGGCAACCTGGCGCTTTACTAGGAGAT---GATCAGATTTATAATGTGATTGTTACTGCCCATGCATTCGTAATAATCTTTTTTATAGTAATGCCCATCATAATCGGAGGCTTCGGAAACTGATTAGTGCCCTTAATAATTGGCGCTCCTGACATAGCATTCCCCCGAATAAATAATATGAGCTTCTGACTTCTACCCCCATCTTTCCTATTACTACTCGCTTCCTCCATAGTAGAAGCAGGTGCAGGAACAGGATGGACCGTATATCCTCCCTTAGCCGGTAATCTAGCCCATGCAGGAGCATCTGTAGACCTAACAATTTTCTCCCTTCACCTAGCAGGTGTATCATCCATTCTTGGGGCTATTAATTTTATCACTACTATTATCAATATAAAACCTCCTGCAATATCTCAATATCAAATTCCCTTATTCGTGTGATCTGTACTAATCACAGCAGTCCTCTTACTATTATCACTACCAGTTCTAGCAGCTGGCATTACTATACTACTTACAGATCGAAACCTGAATACAACATTCTTCGATCCTGCCGGGGGAGGTGATCCCATTCTATACCAACACCTGTTCTGATTCTTTGGACACCCTGAAGTCTACATCCTGATCCTTCCAGGATTCGGAATAATTTCACATATCGTTACCTATTACTCAGGGAAAAAAGAACCTTTCGGTTATATAGGGATAGTCTGAGCAATAATATCCATCGGCTTCCTAGGCTTCATCGTATGGGCCCACCACATATTTACTGTAGGAATGGACGTTGACACACGAG
-- end --

Download FASTA File

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Statistics of barcoding coverage: Hydrurga leptonyx

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 4
Specimens with Barcodes: 4
Species With Barcodes: 1
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Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
LC
Least Concern

Red List Criteria

Version
3.1

Year Assessed
2015

Assessor/s
Hckstdt, L.

Reviewer/s
Kovacs, K.M.

Contributor/s

Justification
The most recent circumpolar estimate of Leopard Seal abundance indicates a total population of more than 35,000 individuals, but this is likely a substantial underestimate. There is no indication of a declining trend in the population, although abundance estimates have considerable uncertainty around them and consequently trend is unknown. Leopard Seals depend on sea ice for reproduction and at some time in the future they could be adversely affected by a reduction in sea ice due to continued climate warming. Leopard Seals are currently a widespread and abundant species that does not qualify for any of the IUCN threatened categories, and they should be listed as Least Concern.

History
  • Least Concern (LC)
  • 1996
    Lower Risk/least concern (LR/lc)
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According to the IUCN Red List, leopard seals are at lower risk and of least concern. However, a decline in antarctic pack ice will likely to be impact the species.

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

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Population

Population
The Leopard Seal is a widespread species and, similar to the other Antarctic seals that inhabit the pack ice, population assessments are very difficult and expensive to conduct and therefore undertaken infrequently. Published global population estimates from many decades ago range from 100,000-300,000 (Scheffer 1958) up to 220,000-440,000 animals (Laws 1984). However, these early estimates were based on very limited sampling and were highly speculative. An analysis of ship and aerial sighting surveys carried out around the continent between 1968 and 1983 provided a point estimate for global Leopard Seal population size in the pelagic pack ice of the Southern Ocean of 300,000 animals (Erickson and Hanson 1990). The most ambitious and coordinated effort to date, the Antarctic Pack-Ice Seal (APIS) project, conducted aerial and shipboard surveys around the continent during 1996-2001, and also included deployment of satellite-linked dive recorders to investigate haulout behaviour. APIS surveys resulted in an estimate of 35,500 (95% CL 10,900-102,600) Leopard Seals in the surveyed areas (Southwell et al. 2012). All estimates have considerable uncertainty associated with them, and only very large changes in Leopard Seal population size could be confidently detected from repeated surveys (Southwell et al. 2008).

Population Trend
Unknown
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Threats

Major Threats
There are currently no major threats from human activity within the species normal range.

Learmonth et al. (2006) list the effects of global climate change on Leopard Seals as unknown. However, loss of sufficient areas of pack ice habitat suitable for pupping, resting and avoidance of predators, and availability of preferred prey such as Penguins, other Seals, Krill and fish that might all possibly decline, could effect Leopard Seals directly or indirectly to an unknown degree. The effects of loss of large amounts of ice on the Antarctic continent, general climate warming, or sea level rises, on Antarctic ocean circulation and productivity and on Antarctic marine resources such as Seals are unknown.Siniff et al. (2008) suggested that similar to Crabeater Seals, Leopard Seals would be less affected by changes in sea ice than Ross or Weddell Seals.

Two species of Antarctic ice seals, Leopard and Crabeater, have tested positive for antibodies to canine distemper virus (CDV). The effects of an outbreak of this or other diseases on Leopard Seals either as a disease within this species, or repeatedly transmitted to it from an outbreak in a prey species such as the Crabeater Seal, are unknown. Leopard Seals are generally solitary except when females attend their pup or when pairs mate, so transmission of disease within the species would likely be slow or only seasonally significant. CDV is believed to have arrived in the Antarctic with sled dogs before the advent of vaccines. A mass mortality of Crabeater Seals occurred in 1955, with many animals displaying viral illness symptoms prior to death, but the exact cause of death is unknown (Bengtson and Boveng 1991).

Seasonal tourism in the Antarctic and Sub-Antarctic has increased steadily in the last 30 plus years, and is currently at all-time high levels. The effects of increased vessel noise, disturbance from vessels passage, and close approaches by people in small boats and on land on Leopard Seal behaviour, distribution and foraging are unknown. There is also a risk of injury to a small number of animals from collision with boats or crushing from large vessels passing through ice fields.

There are no reports of significant fisheries interactions. Commercial harvest of Krill may pose direct or indirect threats to Leopard Seals, if conducted on a large scale.
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Management

Conservation Actions

Conservation Actions
The Leopard Seal is not listed as endangered or threatened on any national Red List. Under the Antarctic Treaty's Convention for the Conservation of Antarctic Seals, the global quota set for Leopard Seals is 12,000 animals annually, but currently there is no harvesting.
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Relevance to Humans and Ecosystems

Benefits

Leopard seals have no observed negative economic effects on humans.

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There are few interactions between humans and leopard seals, however they are used for scientific research and education.

Positive Impacts: research and education

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Wikipedia

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). Along with all of the other earless seals, it belongs to the family Phocidae, and is the only species in the genus Hydrurga. The name hydrurga means "water worker" and leptonyx is the Greek for "small clawed".

Description[edit]

The skull of the leopard seal

The leopard seal is large and muscular, with a dark grey back and light grey on its stomach. Its throat is whitish with the black spots that give the seal its common name. Females are slightly larger than the males.[3] The overall length of this seal is 2.4–3.5 m (8.4–11.7 ft) and weight is from 200 to 600 kilograms (440 to 1,320 lb). They are about the same length as the northern walrus, but usually less than half the weight.[4][5]

Its front teeth are sharp like those of other carnivores, but its molars lock together in a way that allows them to sieve krill from the water, in the manner of the crab eater seal.

Distribution[edit]

The leopard seal lives in the cold waters surrounding the Antarctic continent. Where most seals remain restricted within the pack ice throughout the year, [6] [7] some (mostly young animals) move further north in the austral winter to subantarctic islands and the coastlines of the southern continents. They are difficult to survey by traditional visual techniques [8] this is because they spend long periods of time vocalizing under the water during the austral spring and summer - when visual surveys are carried out. This trait of vocalizing underwater for long periods however has made them available to acoustic surveys. [9] Leopard seals are solitary and widely distributed throughout the pack ice. Higher densities of leopard seals are seen in the Western Antarctic than in other regions.[10] [11]

Behaviour[edit]

A leopard seal growling

Acoustic behavior[edit]

Leopard seals are very vocal underwater during the austral summer. [12] The male seals produce loud call (153 to 177 dB re 1 μPa at 1 m) for many hours each day. [13] While singing the seal’s hang upside down and rock from side to side under the water. Their back is bent, the neck and cranial thoracic region (the chest) is inflated and as they call their chest pulses. Adult male leopard seals have only a few stylized calls some are like bird or cricket-like trills yet others are low haunting moans. [14] The leopard seals have age-related differences in their calling patterns, just like birds. Where the younger male seals have many different types of variable calls - the adult male seals have only a few, highly stylized calls.[15] Each male seal produces individually distinctive songs. They arrange their few call types into individually distinctive sequences (or songs).[16]The acoustic behavior of the leopard seal is believed to be linked to their breeding behaviour. In male seals vocalizing coincides with the timing of their breeding season, which falls between November and the first week of January, and in captive female seals vocalize, when they have elevated reproductive hormones. [17]

Breeding behavior[edit]

The females give birth to a single pup during the austral summer on the floating ice floes of the Antarctic pack ice. She protects the pup until it is able to fend for itself.

The leopard seal is bold, powerful and curious. In the water, there is a fine line between curiosity and predatory behaviour, and it may 'play' with penguins it does not intend to eat. There are also records of leopard seals attacking divers. Paul Nicklen, a National Geographic magazine photographer, captured pictures of a leopard seal bringing live, injured, and then dead penguins to him, possibly in an attempt to teach the photographer how to hunt.[18]

Foraging behavior[edit]

Leopard seal feeding on emperor penguin.

The leopard seal is second only to the killer whale among Antarctica's top predators. Its canine teeth are 2.5 cm (1 in).[19] It feeds on a wide variety of creatures. Smaller seals probably eat mostly krill, but also squid and fish. Larger leopard seals probably switch from krill to more substantial prey, including king, adelie, rockhopper, gentoo, emperor, and chinstrap penguins, and less frequently, other seals, such as crabeater seal.

Around the sub-Antarctic island of South Georgia, the Antarctic fur seal (Arctocephalus gazella) is the main prey. Other prey include penguins and fish. Antarctic krill (Euphausia superba), southern elephant seal (Mirounga leonina) pups and seabirds other than penguins have also been found in leopard seal scats in small quantities.[20]

When hunting penguins, the leopard seal patrols the waters near the edges of the ice, almost completely submerged, waiting for the birds to enter the ocean. It kills the swimming bird by grabbing the feet, then shaking the penguin vigorously and beating its body against the surface of the water repeatedly until the penguin is dead. Previous reports stating the leopard seal skins its prey before feeding have been found to be incorrect. Lacking the teeth necessary to slice its prey into manageable pieces, it flails its prey from side to side tearing and ripping it into smaller pieces.

Phylogeny[edit]

The leopard seal is classified within the family Phocidae. Its closest relatives are the Ross seal, crabeater seal and the Weddell seal, which together are known as the lobodontine seals. All these seals descend from the superfamily Pinnipeda, which evolved from bear-like ancestors. They have diverged from other taxa in the order Carnivora.

The leopard seal share homologous features with its close relatives, the lobodontine seals. They all have dark fur on the tops of their bodies and lighter fur on their underbellies. Though the colors vary between these species, the colored fur serves the same function of camouflaging the individual to conceal it from both predator and prey.

Attacks on humans[edit]

Leopard seals are potentially highly dangerous towards humans, but attacks are rarely reported.[21] Examples of aggressive behaviour, stalking and attacks have been documented.[22] Notable incidents include:

  • A large leopard seal attacked Thomas Orde-Lees (1877–1958), a member of Sir Ernest Shackleton's Imperial Trans-Antarctic Expedition of 1914–1917 when the expedition was camping on the sea ice.[21] A large "sea leopard" of about 12 ft (3.7 m) long and 1,100 lb (500 kg) chased Orde-Lees on the ice. He was saved only when another member of the expedition shot the animal.
  • In 1985, Scottish explorer Gareth Wood was bitten twice on the leg when a leopard seal tried to drag him off the ice and into the sea. His companions managed to save him by repeatedly kicking the animal in the head with the spiked crampons on their boots.[21][22]
  • In 2003, a leopard seal dragged snorkeling biologist Kirsty Brown of the British Antarctic Survey nearly 200 ft (61 m) underwater to her death, in what was identified as the first known human fatality from a leopard seal.[21][22]

Leopard seals have shown a particular predilection for attacking the black, torpedo-shaped pontoons of rigid inflatable boats, necessitating researchers to equip their craft with special protective guards to prevent them from being punctured.[22][23]

Notes and references[edit]

  1. ^ Wozencraft, W. C. (2005). "Order Carnivora". In Wilson, D. E.; Reeder, D. M. Mammal Species of the World (3rd ed.). Johns Hopkins University Press. ISBN 978-0-8018-8221-0. OCLC 62265494. 
  2. ^ Southwell, C. (2008). Hydrurga leptonyx. In: IUCN 2008. IUCN Red List of Threatened Species. Retrieved 28 January 2009.
  3. ^ Tunstall, T. "Hydrurga leptonyx". Animal Diversity Web. University of Michigan Museum of Zoology. Retrieved 2009-04-27. 
  4. ^ Nowak, Ronald M (2003). Walker's Marine Mammals of the World. Johns Hopkins University Press: Baltimore, MD. 
  5. ^ Leopard Seals, Hydrurga leptonyx. marinebio.org
  6. ^ Rogers, T.L., Hogg, C., and Irvine, A. (2005). "Spatial movement of adult leopard seals (Hydrurga leptonyx) in Prydz Bay, Eastern Antarctica.". Polar Biology 28 (6): 456–463. doi:10.1007/s00300-004-0703-4. 
  7. ^ Meade, J., Ciaglia, M.B., Slip, D.J., Negrete, J., Márquez M.E.I., Rogers, T. (2015). "Spatial patterns in activity of leopard seals Hydrurga leptonyx in relation to sea ice.". Marine Ecology Progress Series 521: 265–275. doi:10.3354/meps11120. 
  8. ^ Southwell, C., Paxton, C., Borchers, D., Boveng, P. Rogers, T., and de la Mare, W. (2008). "Uncommon or cryptic? Challenges in estimating leopard seal abundance by conventional but state-of-the-art methods.". Deep Sea Research Part I: Oceanographic Research Papers 55 (4): 519–531. doi:10.1016/j.dsr.2008.01.005. 
  9. ^ Rogers TL, Ciaglia MB, Klinck H, Southwell C (2013). "Density Can Be Misleading for Low-Density Species: Benefits of Passive Acoustic Monitoring.". PLoS ONE 8 (1): e52542. doi:10.1371/journal.pone.0052542. 
  10. ^ Southwell, C., Bengtson, J., Bester, M., Schytte Blix, A., Bornemann, H., Boveng, P., Cameron, M., Forcada, J., Laake, J., Nordøy, E., Plötz, J., Rogers, T., Southwell, D., Steinhage, D., Stewart, B.S., Trathan, P (2012). "A review of data on abundance, trends in abundance, habitat use and diet of ice-breeding seals in the Southern Ocean.". CCAMLR Science 19: 1–26. 
  11. ^ Forcada, J., Trathan, P., Boveng, Boyd, I., Burns, J., Costa, D., Fedak, M., Rogers, T., Southwell, C. (2012). "Responses of Antarctic pack-ice seals to environmental change and increasing krill fishing.". Biological Conservation 149 (1): 40–50. doi:10.1016/j.biocon.2012.02.002. 
  12. ^ Rogers TL, Ciaglia MB, Klinck H, Southwell C (2013). "Density Can Be Misleading for Low-Density Species: Benefits of Passive Acoustic Monitoring.". PLoS ONE 8 (1): e52542. doi:10.1371/journal.pone.0052542. 
  13. ^ Rogers TL (2014). "Source levels of the underwater calls of a male leopard seal". The Journal of the Acoustical Society of America. 136 (4): 1495–1498. doi:10.1121/1.4895685. 
  14. ^ Rogers, T. L., Cato, D. H., & Bryden, M. M. (1996). "Behavioral significance of underwater vocalizations of captive leopard seals, Hydrurga leptonyx.". Marine Mammal Science 12 (3): 414–427. doi:10.1111/j.1748-7692.1996.tb00593.x. 
  15. ^ Rogers, T. L (2007). "Age-related differences in the acoustic characteristics of male leopard seals, Hydrurga leptonyx.". The Journal of the Acoustical Society of America 122 (1): 596. doi:10.1121/1.2736976.x. 
  16. ^ Rogers, Tracey L. and Cato, Douglas H. (2002). "Individual Variation in the Acoustic Behaviour of the Adult Male Leopard Seal, Hydrurga leptonyx". Behaviour 139 (10): 1267–1286. doi:10.1163/156853902321104154. JSTOR 4535987. 
  17. ^ Rogers, T. L., Cato, D. H., & Bryden, M. M. (1996). "Behavioral significance of underwater vocalizations of captive leopard seals, Hydrurga leptonyx.". Marine Mammal Science 12 (3): 414–427. doi:10.1111/j.1748-7692.1996.tb00593.x. 
  18. ^ http://www.dpreview.com/news/2012/10/18/National-Geographic-Photographer-Paul-Nicklen-surprise-encounter-with-Leopard-Seal-Antarctica
  19. ^ Kindersley, Dorling (2005) [2001]. Animal. New York City: DK Publishing. ISBN 0-7894-7764-5. 
  20. ^ Walker, T.R., Boyd, I.L., Mccafferty, D.J., Huin, N., Taylor, R.I., Reid, K. (1998). "Seasonal occurrence and diet of leopard seals (Hydrurga leptonyx) at Bird Island, South Georgia". Antarctic Science 10 (1): 75–81. doi:10.1017/S0954102098000108. 
  21. ^ a b c d Carrington, Damian (2003-07-24). Inquiry into fatal leopard seal attack begins. NewScientist.com. Retrieved on 2013-02-24.
  22. ^ a b c d Owen, James (August 6, 2003). "Leopard Seal Kills Scientist in Antarctica". National Geographic Society. Retrieved 2007-12-10. 
  23. ^ Briggs, Mike; Briggs, Peggy (2005). The Encyclopedia of World Wildlife. Parragon. p. 60. ISBN 1-40545-680-9. 

General references[edit]

  • Rogers, Tracey L. (2002). Leopard Seal. In William F. Perrin, Bernd Würsig & J.G.M. Thewissen eds. Encyclopedia of Marine Mammals San Diego: Academic Press. 692–693.
  • Rogers, T. (2009). The leopard seal, Hydrurga leptonyx. In W. F. Perrin, B. Wursig, & J. G. M. Thewissen (Eds.), Encyclopedia of Marine Mammals (Second ed., pp. 673-674). San Diego: Academic Press
  • National Geographic Magazine, November 2006 Leopard Seals
  • Saundry, Peter. (2010) http://www.eoearth.org/wiki/Leopard_seal Leopard Seal]. Encyclopedia of Earth. Topic ed. C.Michael Hogan, ed. in chief Cutler Cleveland, NCSE, Washington DC
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