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Kingdom
Animalia
Phylum
Chordata
Subphylum
Vertebrata
Class
Mammalia
Order
Carnivora
Suborder
Caniformia
Family
Phocidae
Species
Hydrurga leptonyx
Hydrurga leptonyx
leopard seal
2010/02/07 03:10:35.426 US/Eastern
By Tate Tunstall
Species:
Hydrurga leptonyx
Geographic Range
Hydrurga leptonyx
is most common in the polar and subpolar waters of the Southern Hemisphere, along the coast of Antarctica and on most sub-Antarctic islands. Some individuals can be found on the coasts of South Africa, southern Australia, Tasmania, New Zealand, Lord Howe Island, the Cook Islands, Tierra del Fuego, and the Atlantic coast of South America.
(
Jefferson, Leatherwood, and Webber, 1993
;
Nowak, 1999
)
Habitat
Terrestrial Biomes:
icecap.
Physical Description
Mass
200 to 591 kg
(440 to 1300.2 lbs)
Length
241 to 338 cm
(94.88 to 133.07 in)
Adults of
H. leptonyx
reach 241-338 cm in length, with females being on average slightly larger than males. The body is streamlined and massive, with a very large head and long, broad foreflippers. Leopard seals swim with long, powerful, simultaneous strokes of the forelimbs, unlike most other phocids which propel themselves by means of side-to-side strokes of the hindlimbs. Coloration is dark above giving way to silvery pale on the sides and below, with varying degrees of spotting. In addition to having well developed canines, the cheek teeth of the leopard seal consist of three tubercles or lobes, similar to those of the crabeater seal,
Lobodon carcinophaga
. These complex teeth allow the leopard seal to filter krill from the water.
(
Jefferson, Leatherwood, and Webber, 1993
;
Nowak, 1999
)
Reproduction
Breeding season
Mating occurs in the water from November to February.
Number of offspring
1 (average)
Gestation period
11 months (average)
Time to weaning
4 weeks (high)
Time to independence
4 weeks (high)
Age at sexual or reproductive maturity (female)
3 years (average)
Age at sexual or reproductive maturity (male)
4 years (average)
Male leopard seals reach sexual maturity around their fourth year, females in their third. Mating occurs in the water from November to February. Gestation lasts around 11 months, but implantation seems to be delayed for about 2 months. Parturition occurs from September to January, with the concentration of births in October and November.
(
Nowak, 1999
;
Siniff and Stone, 1985
)
The female gives birth to a single pup weighing about 30 kg and about 160 cm long. Lactation can persist for up to four weeks. The pup's coat is soft and thick, dark grey above with a dorsal stripe, pale on the sides and with black spots below. Males do not seem to participate in parental care.
Parental investment:
precocial
; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female).
Behavior
The leopard seal is primarily a solitary species. Animals of different age groups are often segregated in different areas. Mature animals normally occur on the outer fringes of the pack ice. Young animal disperse to sub-Antarctic islands during the winter, and it is debated whether or not these movements are migrations or periodic dispersals due to intraspecific competition.
(
Borsa, 1990
;
King, 1983
;
Rogers, Cato, and Bryden, 1996
)
Communication and Perception
Leopard seals are capable of producing a variety of vocalizations, which have been correlated with different body movements and postures. The vocalizations have been associated with intraspecific agression, female receptivity, and males searching for mates.
(
Borsa, 1990
;
King, 1983
;
Rogers, Cato, and Bryden, 1996
)
Food Habits
The diet of the leopard seal is quite variable, and it is the only pinniped in which warm blooded vertebrates make up a large portion of the diet.
Crabeater
and fur seals (in the genus
Arctocephalus
) often bear scars from leopard seal attacks. Prey has been estimated at 45 percent krill, 35 percent seals, 10 percent
penguins
, and 10 percent fish and cephalopods, but proportions will vary along with age, seasonal abundance of food, and location. Leopard seals have also been known to scavenge the carrion of whales and other seals.
(
Boveng et al., 1998
;
King, 1983
;
Kooyman, 1981
;
Siniff and Stone, 1985
)
Primary Diet:
carnivore
(eats terrestrial vertebrates, eats non-insect arthropods).
Animal Foods:
birds; mammals; fish; mollusks; aquatic crustaceans.
Predation
There are few natural predators of leopard seals. They are top carnivores in Antarctic ecosystems. However, they may occasionally be taken by orcas (
Orca orcinus
) or large sharks.
Economic Importance for Humans: Negative
There are no known adverse affects of leopard seals on humans.
Economic Importance for Humans: Positive
Conservation Status
IUCN Red List:
[link]
:
Lower Risk - Least Concern.
US Federal List:
[link]
:
No special status.
CITES:
[link]
:
No special status.
Leopard seal populations are abundant in preferred habitat and the species is not exploited by man. Leopard seals, especially young, seasonally depend on krill, but are less competitive than other krill-feeding species.Leopard seals could, therefore, be one of the first species adversely affected by commercial krill fisheries. The species is currently rated as Lower Risk/Least Concern by the International Union for the Conservation of Nature.
(
Jefferson, Leatherwood, and Webber, 1993
;
Nowak, 1999
;
Siniff and Stone, 1985
)
For More Information
Find
Hydrurga leptonyx
information at
Contributors
Tate Tunstall (author), University of California-Berkeley.
James Patton (editor), University of California-Berkeley. Tanya Dewey (editor), Animal Diversity Web, University of Michigan Museum of Zoology.
References
Borsa, P. 1990. Seasonal occurance of the Leopard seal, Hydrurga leoptonyx, in the Kerguelen Islands.
Canadian Journal of Zoology
, 68(2): 405-408.
Boveng, P., L. Hiruki, M. Schwartz, J. Bengtson. 1998. Population growth of Antarctic Fur Seals: Limitation by a top predator, the Leopard seal?.
Ecology
, 79(8): 2863-2877.
Jefferson, T., S. Leatherwood, M. Webber. 1993.
Marine Mammals of the World
. Rome: United Nations Environment Programme, Food and Agriculture Organization of the United Nations.
King, J. 1983.
Seals of the World 2nd Edition
. Ithaca, New York: Comstock Publishing Associates a division of Cornell University Press.
Kooyman, G. 1981. Leopard Seal-Hydrurga leptonyx. Pp. 261-274 in S. Ridgway, R. Harrison, eds.
Handbook of Marine Mammals
. London: Academic Press Inc..
Nowak, R. 1999.
Walker's Mammals of the World, 6th Edition
. Baltimore: The Johns Hopkins University Press.
Rogers, T., D. Cato, M. Bryden. 1996. Behavioral significance of underwater vocalizations of captive leopard seals, Hydrurga leptonyx.
Marine Mammal Science
, 12(3): 414-427.
Siniff, D., S. Stone. 1985. The role of the Leopard seal Hydrurga leptonyx in the tropho-dynamics of the Antarctic Marine Ecosystems. Pp. 555-560 in W. Seigfried, P. Condy, R. Laws, eds.
Antarctic Nutrient Cycles and Food Webs
. Berlin: Springer-Verlag.
2010/02/07 03:10:37.532 US/Eastern
To cite this page:
Tunstall, T. 2000. "Hydrurga leptonyx" (On-line), Animal Diversity Web. Accessed February 09, 2010 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Hydrurga_leptonyx.html.
Disclaimer:
The Animal Diversity Web is an educational resource
written largely by and for college students
. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.
Other formats:
OWL
Sponsored in part by the Interagency Education Research Initiative,
the Homeland Foundation and the
University of Michigan
Museum of Zoology
.
This material is based upon work supported by the
National Science Foundation
under Grants DUE-0633095 and DRL-0628151.
The ADW Team gratefully acknowledges their support.
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