By Helen Edwards
Geographic Range
The breeding range of Arctocephalus gazella is primarily restricted to seasonally ice free islands south of the Antarctic Convergence, but individuals have been found as far north as Brazil. Some adult males and juveniles stay ashore year round, but the direction of the female migrations in the Southern ocean are unknown.
Biogeographic Regions:
neotropical 
(native ); australian (native ); oceanic islands (native ); atlantic ocean (native ); pacific ocean (native ).
Habitat
Though the species appears to be capable of travelling long distances over ice, it doesn't seem well adapted to such an environment. Breeding occurs on rocky beaches sheltered from the sea. The islands they inhabit commonly support lush grass growth inland. During the months of May and November, there is a general movement out to sea, but specific migration paths are unknown. Some adult males are found ashore or in the general area of the breeding islands year-round.
These animals are found in the following types of habitat:
polar ; saltwater or marine .
Physical Description
(66 to 264 lbs; avg. 143 lbs)
Known as "eared seals" due to their external ear flaps (pinnae), these seals stand with the fore and hind limbs under the body, pointing forward. Extreme sexual dimorphism is evident in A. gazella, with the males weighing between 60 and 120 kg and the females weighing between 30 and 51 kg. Adult males are 1-2 m long, whereas the females vary between .5 and 1 m. The adults are covered in a dense velvety underpelt, which is both waterproof and windproof, and an outer layer of coarse grey-brown hair. The males can be distinguished from the females by their long mane of shoulder fur. At birth, pups weigh between 4.5 and 6.5 kg and measure a length of between 60 and 73 cm. The pups have black wooly fur, which is retained for 2-3 months. The pups then display a silver-grey coat which lasts until adulthood.
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: male larger, ornamentation .
Reproduction
Females give birth once each year.
Breeding occurs from November to January, the southern hemisphere summer.
In this polygynous mating system, a dominance hierarchy of males is established through the displays and fights that occur while defending territories. Some subordinate males are forced inland while others assume a completely aquatic lifestyle.
Mating systems:
polygynous .
The breeding season of this species is from November to January. The males arrive earlier than the females to compete for territories, which will eventually hold a harem of 4-5 females. The competition is fierce and males don't feed while defending their territories on shore. Breeding incurs significant costs to the males of the species, which lose an average of 1.5 kg a day throughout the season. Females give birth to a single young approximately two days after arrival on shore. The females become sexually receptive 6-8 days after giving birth and then begin mating.
Key reproductive features:
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; viviparous .
During lactation, females spend 3-5 days feeding at sea to maintain their supply of milk. This period is followed by 1-2 days of nursing on shore. This cycle is repeated for 4 months. The lactation period is one of the shortest of all fur seals and is probably due to the harsh weather conditions and strong seasonality of the breeding area. While the female is away, the pup hides in a sheltered area. Both the mothers and the pups use vocalization as a means to relocate each other when the mothers return from the sea.
Parental investment:
altricial ; pre-fertilization (provisioning, protecting: female); pre-hatching/birth (provisioning: female, protecting: female); pre-weaning/fledging (provisioning: female, protecting: female).
Behavior
Arctocephalus gazella is surprising agile on land, reaching speeds of 20 km/hr on smooth surfaces. It is quite probable that they reach even higher speeds in the water. Using time-depth recorders, the dives of several lactating females have been measured. The deepest dives average about 181 m and last almost 5 minutes.
Key behaviors:
natatorial ; motile ; territorial ; social ; dominance hierarchies .
Food Habits
The main food of the Antarctic fur seal is krill, but individuals also consume squids and even birds. Nursing mothers are almost completely dependent on krill and the reproductive success of this species is, therefore, closely linked with the availability of this food resource. Arctocephalus gazella mainly feed at night in the shallower waters of the ocean.
Primary Diet:
carnivore (eats non-insect arthropods).
Animal Foods:
birds; fish; mollusks; aquatic crustaceans.
Economic Importance for Humans: Negative
Commercial krill harvesting is now being developed in small countries and this move threatens to begin a battle between human interests and those of the Antarctic fur seal.
Economic Importance for Humans: Positive
Although the Antarctic fur seal is no longer of economic importance to humans, the species was heavily hunted throughout the 18th and 19th centuries for its fur.
Ways that people benefit from these animals:
body parts are source of valuable material.
Conservation Status
IUCN Red List: [link]:
Lower Risk - Least Concern.
US Federal List: [link]:
No special status.
CITES: [link]:
Appendix II.
This species almost became extinct in the 18th and 19th centuries due to intense commercial sealing for their fur. The population growth has now reached about 10% per annum due to increasing concern about their well-being. They are protected under the Convention for Conservation of Antarctic Seals (CCAS) and the Antarctic Treaty. On a more local level they are protected by the legislation of each of the islands they inhabit. They have also been placed under Appendix II of CITES.
For More Information
Find Arctocephalus gazella information at
Contributors
Helen Edwards (author), University of Michigan.
Phil Myers (editor), Museum of Zoology, University of Michigan.
